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Dec 27
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Oxy-Acetylene Welding Discussed | Gasoline Welding

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Gasoline welding is one of the oldest sorts of warmth-centered welding, which makes use of oxygen and gas fuel to sign up for metals. At a person issue in time, gasoline welding was just about the only procedure that could produce top quality welds in most commercially utilized metals. Since then, more recent welding types have taken above as they are additional effective, supply increased top quality, and are improved in quite a few key places.

In spite of all that, the fuel welding process continue to has its put among hobbyists and smaller sized metal workshops owing to its simplicity and extensive scope of programs. Even so, its usage is now typically constrained to thinner inventory and mend operations.

What Is Gas Welding?

Fuel welding or oxy-fuel welding is a procedure that utilizes warmth created from burning a mix of diverse gases to soften and fuse metals. Even though it is possible to be a part of the metal workpieces with no any further filler product, the use of filler rods is inspired to ensure potent and lasting welds.

Not like most procedures that use energy to build heat (arc welding approaches like MIG, TIG, and SMAW), the flame from fuel welding is produced by just burning a mixture of gases. Oxygen and acetylene are regarded as the most important fuel mixture because it is the most successful in generating heat to weld steel, as a result making the system regarded as oxy-gasoline or oxy-acetylene welding.

Other gasoline gases utilized in the system are propane, hydrogen and coal gasoline. These combos can be utilized for welding non-ferrous metals and distinct purposes this kind of as brazing and silver soldering.

The very same oxy-welding machines can be applied for oxy-acetylene chopping by changing the flame profile and including a instead affordable reducing attachment. The chopping torch features an oxygen-blast cause encouraging to burn up and blast the molten metal out of the minimize.

Oxy-Gasoline Welding Process

Oxyacetylene welding employs the idea of building heat from the combustion of oxygen and fuel gas. Gas supply stored in superior-force cylinders flows by means of the adaptable hoses (an oxygen hose and a fuel fuel hose) by changing the gasoline regulators. The gases are blended in the mixing chamber of the hand-held oxy-gas torch and exit via the orifice in the idea. Welding suggestion orifice dimensions is an important variable and thus, it should be chosen in accordance with the software.

As warmth is applied to the base metal, it reaches a melting issue (about 3200°C), whereby fusion welding happens. Other welding methods that use electric power can get to better temperatures (over 5000°C), generating oxyacetylene welding most appropriate for slender metals. Applying filler rods is optional and is dependent on the scope of the challenge.

Since gas welding operates with flamable products, it is important to apply appropriate security measures.

Kinds of Flames

The form of welding flame plays an essential role in analyzing the ensuing weld joint and its qualities. The flame profile is manipulated by adjusting the gasoline gas and oxygen move fee.

Bigger amounts of oxygen lead to a hotter flame, which might bring about the metal to warp. A colder flame takes place when the volume of gasoline gasoline is better than oxygen, which may cause inadequate weld high quality.

Neutral Flame

Equivalent quantities of welding gases by quantity result in a neutral flame. The entire combustion of the gas gasoline and compressed oxygen implies that the homes of the weld metals aren’t impacted while making nominal smoke at the similar time.

This welding flame has two zones, a white inner zone of about 3100°C and a blue outer zone with a temperature of about 1275°C. Neutral flame is chosen when welding metals these types of as forged iron, delicate steel and stainless steel.

Carburising Flame

Carburising aka cutting down flame is accomplished by supplying increased quantities of gasoline gas in comparison to pure oxygen. The flame made is smoky and has a peaceful flame that chemically sorts metal carbide.

Three zones are developed in this flame: a white interior zone (2900°C), a purple intermediate zone (2500°C), and a blue outer zone (1275°C). Carburising flame is most well-liked for welding nickel, steel alloys and non-ferrous metals.

Oxidising Flame

Oxidising flames are created when the supplied gas from the oxygen cylinder is higher than the gasoline gas – the surplus oxygen effects in increased flame temperatures exiting the welding torch than neutral flame.

This variety of flame makes two zones, a white interior zone at all-around 3500°C and a blue outer zone at 1275°C. Oxidising flame is utilized for welding metals these kinds of as brass, copper, bronze and zinc.

Welding Tactics

Leftward

The torch travels from the suitable to the joint’s still left side with a tip forming a 60-70 degree work angle to the workpiece. The filler materials is angled at 30 to 40 degrees to the plate. Three movements create uniform fusion by way of its flame: round, rotational, or side-to-aspect.

Leftward welding is generally utilized to weld unbevelled plates up to 5mm, cast iron, and non-ferrous metals.

Rightward

Reverse to leftward welding, the rightward method starts off at the remaining aspect of the joint and travels toward the ideal end. An angle of 40-50 levels is established among the torch suggestion and the workpiece, whilst the filler rod makes a 30-40 diploma angle to the do the job material.

Rightward welding is commonly more rapidly than leftward welding, with a lot less distortion, and filler metal eaten. It produces denser and much better welds, which are best for security against contamination.

All-Positional Rightward

This method is a modification to rightward welding made use of mainly for steel plate welding, also some pipework and butt welds (5-8mm thick) wherein entire check out and movement are necessary.

Vertical

The joint is established with an oscillating rod and torch travelling from the base towards the top. The rod will make a 30-degree angle, though the torch tends to make a 25 to 90-degree angle with the workpiece, depending on its thickness.

A single operator may perhaps use this system for steel plates up to 5 mm thick, even though two operators operating in harmony are demanded for thicker metals.

Supplies

  • Aluminium

  • Brass

  • Bronze

  • Carbon steels

  • Solid iron

  • Copper

  • Magnesium

  • Moderate steel

  • Nickel

  • Stainless steel

  • Steel alloys

  • Zinc

Positive aspects of Gas Welding

  1. The system is suitable for a wide variety of ferrous and non-ferrous metals.

  2. Gas welding doesn’t call for energy.

  3. It is a simple and uncomplicated welding strategy.

  4. Gas welding gear is low-priced and transportable compared to other welding processes.

Down sides of Fuel Welding

  1. Gas welding offers fewer penetration and heat than arc welding procedures, this kind of as TIG and MIG welding.

  2. The process necessitates publish-weld finishing to enhance its aesthetic seem.

  3. Oxyacetylene welding is susceptible to weld flaws considering that it does not have weld pool shielding.

  4. Gas welding has a slower level of heating and cooling in comparison to modern day techniques.

  5. It is not appropriate for welding significant-power steel considering the fact that it can alter its mechanical qualities.

Wrapping It Up

Oxy-gasoline welding is one of the pioneers of the industrial revolution, featuring flexibility in its vast variety of applications. Today, it is not considerably utilised in industries as it has been before, as newer and extra revolutionary welding methods have replaced it. Even now, fuel welding continues to be a trustworthy decision for some applications and is desired by some hobbyists and specialists.

Dec 21
0

Tempering Explained | Definition, Process, Benefits and More

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Tempering is one of many heat treatment processes for iron-based alloys. These processes alter the physical and mechanical properties such as a metal’s internal structure, ductility, hardness, toughness, machinability, formability, elasticity and strength.

We need these changes to ensure metals are fit for their applications and service environments. Without heat treatment, it is not possible to use metals to their full capacity in most systems.

In this article, we will explore the tempering process. Let’s begin.

What Is Tempering?

Tempering, also referred to as drawing,  is a heat treatment process in which the components are heated and held to a set temperature below the critical point for a certain duration. The components are then cooled to room temperature in still air.

Like other heat treatment processes such as annealing and normalising, the tempering process alters the metal’s undesirable mechanical properties to be more in line with the proposed application.

Tempering affects the entire component’s mechanical properties from the surface to the core. But partial tempering is also possible in induction plants.

Tempered metals are useful in applications that need a certain level of flexibility from their components.

This heat treatment process may also be used to reduce the hardness of recently welded components. The high localised temperature from the welding process can lead to high hardness in heat-affected zones. Tempering can help us alleviate these high-hardness sections.

In theory, tempering can be carried out on a wide range of metals but it is generally associated with carbon steel as few other metals react to this heat treatment method in the same manner as steel.

When Is Tempering Used?

Tempering is most often performed after hardening processes. In these processes, the material is heated above its upper critical temperature followed by a rapid cooling or quenching operation. Quenching is the immersion of steel in oil, hot water or forced air.

Such an operation makes the material hard and brittle, as brittle as glass in some cases. While we do need high hardness in many applications, the increased brittleness that accompanies it is not as desirable.

To reduce the brittleness and restore ductility, the metals are reheated, this time to lower temperatures. This helps us to strike a balance between hardness and ductility. The cooling rate during tempering is also slower than quenching.

For best results, the tempering process must be carried out immediately after quench-hardening. This helps to avoid the brittle characteristics brought out by the hardening process.

It should be kept in mind that any errors during the process can damage, distort or warp the material.

Tempering is also carried out when the material is hardened through other means such as a welding process. It also works for work-hardened materials. These are materials that have become hard through processes such as bending, drilling, forming, punching and rolling.

The Tempering Process

Like other heat treatment processes, the tempering process occurs in three stages. These stages are:

  1. Heating

  2. Dwelling

  3. Cooling

  1. Heating

In this stage, we heat the metal to a set temperature between room temperature and the lower critical temperature. This temperature is our tempering temperature.

The heating to the exact temperature should happen at a controlled rate because if the metal is heated too quickly, it can lead to cracking. The suitable temperature varies depending on the type of steel and the desired change in properties. For example, tool steels are tempered at a much lower temperatures than springs.

Typically, the metal is heated in a furnace (gas, electrical or induction) in the presence of an inert gas or a vacuum to prevent oxidation. But certain steels are tempered in salt baths or even in the presence of air.

The chosen atmosphere also affects the surface of the components.

  1. Dwelling

Once the metal has achieved the desired temperature below the critical point, it must be held at that temperature for a predetermined duration. The duration depends on the type of steel, component cross-sections, charge size and the required mechanical properties.

Depending on the tempering temperature and dwell time, the mechanical properties of the hardened steel change.

The ductility, impact strength and toughness increase with higher temperatures and dwell time. The ultimate tensile strength, however, will reduce with rising temperatures.

The effect on hardness depends on the share of different phases such as martensite, retained austenite and graphite nodules. As the time in the oven is increased, the martensitic phase reduces and retained austenite increases. As the austenitic phase is relatively softer, the entire component’s hardness reduces.

  1. Cooling

The cooling stage is just as important as the first two. In the cooling process, the component is cooled, usually in the presence of air, in a predetermined manner.

The cooling rate and method used depends on various factors. For tempering, cooling usually takes place in still air.

Tempering Colours

When we heat metal products, they undergo oxidation. This leads to the development of various colours on the metal surface. The colour obtained indicates the tempering temperature.

The colours range from light yellow to various shades of blue. A full list of the colours obtained at different temperature ranges is as follows:

Tempering colour Temperature in C Temperature in F Common applications
Faint yellow 175 – 205 347 – 401 Gravers, razors, scrapers
Straw 205 – 225 401 – 437 Edge tools, knives, reamers, rock drills
Yellow 225 – 250 437 – 482 Planer blades, scribers
Brown 250 – 265 482 – 509 Cold chisels, dies, drill bits, hammers, press tools
Purple 265 – 285 509 – 545 Punches, surgical tools
Blue 285 – 305 545 – 581 Screwdrivers, wrenches
Light blue 305 – 335 581 – 635 Gears, structural steel, springs, wood cutting saws
Grey-blue 335 – 375  635 – 707 Structural steels, springs, wood cutting saws

 

However, these colours do not always indicate the exact tempering temperature. Many other factors such as the alloying elements, atmosphere, surface finish and tempering duration all have an effect on the final colour. For instance, corrosion-proof steels are less prone to oxidation and hence achieve specific tempering colours at higher temperatures than their more corrosion-prone counterparts.

Thus, it is not recommended using this chart to precisely determine the tempering temperatures. These colours should only be taken as an indication to evaluate the metal’s surface temperature during tempering.

The Benefits of Tempering

  • Increased ductility and flexibility

  • Reduced brittleness

  • Excess hardness can be adjusted to acceptable levels

  • Improved microstructure which increases the metal’s strength

  • Relieves internal stresses accrued from prior operations. If left unchecked, residual stresses may cause hydrogen cracking.

  • Increased wear resistance properties of the surface as well as the core. Tempered steel is durable and long-lasting.

  • Increased machinability and formability for succeeding processes

  • Increased toughness

  • Tempering is quicker than the annealing process. Tempered steel is also harder and stronger than annealed steel

Conclusion

Whether you need a safety pin or to build an 80,000-seater stadium, tempering is indispensable. It still remains one of the most important and widely used heat treatment processes in many different applications of steel.

As we advance further into building structures that are more complex than ever, the use of tempered components in manufacturing and construction will only increase with time.

Dec 09
0

Electron Beam Welding (EBW) Explained

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Electron beam welding is a process that utilises the heat from a high-velocity electron beam to form a weld. An electron gun generates the beam through the use of magnetic fields. The kinetic energy from electrons is converted to heat upon contact, thus melting the workpiece and creating a joint.

Let’s cover some key points that make electron beam welding stand out from other welding methods.

What Is Electron Beam Welding?




Electron Beam Welding

Electron beam welding (EBW) uses a high-velocity beam of electrons to melt and fuse metals together. The electron beam can be focused to create a small weld area, which makes it ideal for welding delicate parts or complex designs.  On top of that, EBW works at a rapid rate, making it one of the fastest processes in assembly welding.

Electron beam welding machines are quite complicated, requiring skilled operators to achieve optimal results. On the other hand, it offers a wide range of penetration depth, generally from 0.127 mm to 50 mm/0.005 to 2 inches (although much higher depth can be achieved for certain materials) when using a filler material with the latter, making it stand out compared to common welding techniques like MIG, TIG, and stick welding. EBW fusion welding process run on a single pass creates joints with minimal distortion and possesses the ability to join different metals.

Electron Beam Welding Process

The working principle behind electron beam welding is emitting a focused beam of high-velocity electrons into a joint. This process is usually performed inside a vacuum chamber to improve efficiency and prevent the electron beam from dispersing.

High voltages are supplied into an electron gun, which then expels a high-velocity stream of electrons with the help of cathodes, anodes, focusing coils, and magnetic fields. The intensity of electron beams is 100-1000 times higher than arc welding, allowing deep penetration and narrow heat-affected zones.

EBW different weld profiles
EB weld root inspection – different weld profiles

Similarly to plasma welding, the EBW process can be run in low power, medium power and high power aka keyhole mode. The low power mode is used to produce extremely fine welds, which can be as small as 20µm. Medium power is generally used for weld thicknesses from 1mm to 20mm, anything over that is in the domain of high power electron beam welding. Running the machine in keyhole mode can penetrate up to 300mm of steel and is known to create stable, good-quality welds for material thicknesses over 200mm.

Recent breakthroughs in EBW allow local welding with a workpiece larger than the vacuum chamber adding a bit more versatility to the welding process. This welding technology is achieved by having only the electron beam gun inside a vacuum box while the workpiece itself remains outside of the vacuum chamber.

Materials

The technology behind electron beam welding allows various metals to be welded together, including dissimilar metals, since it is mostly performed in a vacuum environment. EBW is mainly used with these materials:

Equipment

The main components of electron beam welding equipment are the following:

Electron Gun

The main components of an electric gun are the cathode, anode, grid cup and focusing unit. There are two types of electron guns. Self-accelerated electrons are accelerated using the potential difference between the cathode and the anode. Work-accelerated electrons are accelerated using the potential difference between the cathode and the workpiece.

Power Supply

DC power is used in the electron beam welding method with 5-30 volts for small equipment and 70-150 volts for large equipment.

Vacuum Chamber

The pressure for partial vacuum is at 10-2 to 10-3 mbar, while hard vacuum uses a range of 10-4 to 10-5 mbar.

Applications

The diversity of EB welding allows the ability to weld metals with varying thicknesses, making it a flexible option for welding complex parts such as transmission assemblies or small electronic components. It’s also a great option for welding metals with different melting points and thermal conductivities.

As electron beam welding technology is highly automated and delivers a clean result with repeatable accuracy and minimal distortion, there is no need for post-weld machining. Some of the industries benefitting from this include aerospace, automotive, medical, nuclear, oil and gas.

Electron Beam Welding vs Laser Welding

While the basic principle of electron beam welding and laser welding is similar on the surface, there are some distinct differences that make each of them unique:

Heat source

EBW uses a focused beam of electrons, while the laser welding process uses photons to generate heat.

Vacuum environment

Both processes can be performed in a vacuum environment, protecting the weld pool from contamination against air molecules and improving the weld quality. Conventional laser welding is done under atmospheric conditions with the help of inert gas shielding or a combination of gases.

Welding speed

Laser beams require high welding speeds since it vaporises the base materials, creating fumes. The electron beam welding process can accommodate different welding speeds while still achieving deep welds.

Power consumption

Electron beam welding converts around 85% of the electrical input into usable power. In comparison, laser welding only converts up to 40% of electricity to usable power, even with the use of modern tools.

Advantages of Electron Beam Welding

  1. Can reproduce precise welds at rapid weld speeds.

  2. A narrow heat-affected zone allows for welding delicate assemblies.

  3. Clean welds since EBW is done in a vacuum environment.

  4. Ability to join dissimilar metals.

  5. High weld penetration range.

  6. Most penetration depths don’t require filler material.

Disadvantages of Electron Beam Welding

  1. High initial costs.

  2. EBW machinery requires frequent maintenance to function correctly.

  3. The process requires highly skilled machine operators.

  4. The size of the vacuum chamber limits weld size for traditional EBW.

  5. Extreme precaution is required from radiation.

Dec 03
0

Satisfy the team – Rafal

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Becoming a member of Alpha Producing in excess of 9 a long time in the past, Rafal Laczkowski has develop into essential in making certain our products get to our buyers in pristine situation as promptly as possible.

Rafal joined the business in the dispatch division. After just one yr of doing the job within just the staff, Rafal’s challenging operate and motivation have been recognised – earning him a promotion to supervisor level.

Despite his enjoy for his staff and travel to assure his position was accomplished to a substantial standard, Rafal experienced often dreamed of a unique profession route.

Following 8 many years inside Alpha Producing, viewing the opportunities as a result of coaching and expansion offered, Rafal made a decision it was time to chat to Paul Clews, Taking care of Director of Alpha Production, about his childhood aspiration.

Rafal stated, “To be a driver, it was my aspiration. A right dream. Soon after 8 several years doing the job for Alpha Manufacturing, I approached Paul Clews and questioned him if there had been any opportunities to develop into a HGV driver.”

Alpha Manufacturing is dedicated to supporting apprentices and staff to achieve their most effective. This situation was no different. The Alpha management group agreed to cover all prices of Raf’s teaching and ensure him a position as a shipping driver upon completion.

Paul Clews, Handling Director of Alpha Production, reported, “I’m so proud that we have been able to assist Raf get to where by he needed to be. It is significant to us as a small business to know our staff are joyful and fulfilled.”

“A important target of The HEX Group is to ensure our crew has the teaching prospects to attain their objectives.”

Reflecting on the transition to his new aspiration function, Rafal claimed, “I’ve been driving for just more than a yr now. This work is best – from commence to finish.”

“My standard working day starts with vehicle inspections, guaranteeing the car or truck is harmless on the street. Then, it’s time to supervise the merchandise hundreds making sure that every thing is secured effectively to avoid hurt.”

“I can be executing a few of deliveries a day or undertaking just one for a longer time supply to spots these as Southampton. When I’m driving, you can uncover me listening to the likes of Michael Jackson, the Pet Store Boys, and other pop classics to move the time.”

Rafal’s determination to making certain that Alpha Manufacturing’s products get to our consumers is second to none. We appear ahead to sharing much more about his function below soon.

Nov 30
0

Plasma Arc Welding (PAW) Explained

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Plasma welding is an arc welding process that uses a plasma torch to join metals. The principle of this method is derived from GTAW aka TIG welding, where an electric arc is struck between the electrode and the workpiece.

Let’s dig deeper and explore what plasma welding is all about.

What Is Plasma Welding?

Plasma arc welding (PAW) is a fusion welding process that uses a non-consumable electrode and an electric plasma arc to weld metals. Similarly to TIG, the electrode is generally made out of thoriated tungsten. Its unique torch design produces a more focused beam than TIG welding, making it a great choice for welding both thin metals and creating deep narrow welds.

Plasma welding is often used to weld stainless steel, aluminum, and other difficult metals compared to traditional methods. Similarly to oxy-fuel welding, this process can also cut metal (plasma cutting), making it a versatile tool for fabricators and manufacturers.

Plasma Arc Welding Process




Plasma Arc Welding

The plasma arc welding process revolves around the principle of striking an arc between a non-consumable tungsten electrode and the workpiece. The plasma nozzle has a unique design feature, where the electrode is located within the body of the torch. This allows the arc plasma to exit the torch separated from the shielding gas envelope.

Additionally, the narrow opening of the nozzle increases the plasma gas flow rate, allowing for deeper penetration. While filler metal is typically supplied at the weld pool’s leading edge, it is not the case when creating root pass welds.

The complexity of the plasma welding torch sets it apart from gas tungsten arc welding. Plasma welding torches operate at very high temperatures, which can melt away their nozzle, making it a requirement to always be water-cooled. While these torches can be manually operated, nowadays, most modern plasma welding guns are designed for automatic welding.

The most common defects associated with plasma welding are tungsten inclusions and undercutting. Tungsten inclusions occur when the welding current exceeds the capabilities of the tungsten electrode and small droplets of tungsten get entrapped in the weld metal. Undercuts are generally associated with keyhole mode PAW welding and can be avoided by using activated fluxes.

Plasma Arc Welding Operating Modes

Three operating modes are used in plasma welding, wherein it can be operated at varying currents:

Microplasma (0.1 – 15A)

This operating mode can run arcs at low currents and remain stable up to 20mm arc length.

Microplasma welding is used to join thin sheets up to 0.1 mm in thickness, which is optimal for creating wire meshes with minimal distortion.

Medium current (15 – 200A)

The characteristics of the plasma arc are quite similar to TIG welding, but the arc is stiffer since the narrow opening of the torch restricts the plasma. We can increase weld pool penetration by speeding up the plasma flow rate, but this increases the risk of shielding gas contamination.

Medium current or melt-in mode offers better penetration than TIG and improved protection. The only drawback is that the torch requires maintenance and is bulkier compared to a TIG torch.

Keyhole mode (over 100A)

A powerful plasma beam is used to engage in high-current aka keyhole mode by increasing the gas flow and welding current. This mode allows deep penetration, using a single pass (up to 10mm thick for some materials) to create a consistent weld pool from molten metal.

Similarly to electron beam welding, the keyhole mode is great for welding thicker materials at high welding speeds. To guarantee satisfactory welds, filler material is generally added. Its welding applications include mechanised welding, positional welding, and pipe welding.

Comparison of Plasma and TIG Welding

Normally, a tungsten electrode is used in TIG welding to strike an arc between the torch and the workpiece. The plasma process works similarly but uses a different setup in its welding torch. The constricted nozzle design allows electrons to move at high velocities. This ionises the gas, creating a plasma jet with a high heat concentration, offering deeper penetration.

As plasma welding offers greater precision than TIG welding, it has a smaller heat-affected zone which is perfect for creating narrower welds. Ideally, plasma welding is a better choice than TIG welding, as it is an evolution of the latter. The technology behind its equipment allows it to run with lower current demand, better arc stability which leads to better stand-off distance, and better tolerances if the arc length is changed.

TIG welding however is a simpler method due to the complex parameters available for plasma gas welding. An operator would need extra training in order to transition from the already advanced TIG welding to PAW. And last, TIG welding equipment is cheaper and requires less maintenance than plasma arc welding’s sensitive and complex torch.

Materials

Similarly to TIG welding, plasma welding is suitable for the majority of well-known metals, although it might not be the most cost-effective solution for some of them:

  • Alloy Steel

  • Aluminium

  • Bronze

  • Carbon Steel

  • Copper

  • Iron

  • Inconel

  • Lead

  • Magnesium

  • Monel

  • Nickel

  • Stainless Steel

  • Titanium

  • Tool Steel

  • Tungsten

Equipment

The key components of plasma welding equipment are:

Plasma torch

Plasma arc welding (PAW) torch operating principle
Plasma torch – plasma gas is separated from the shielding gas envelope.

 

The unique design of the water-cooled plasma torch is the main distinguishing factor from other welding processes. Its operating principles have already been explained in previous sections.

Depending on the weld material and desired weld characteristics, different types of nozzle tips can be selected.

Control console

While conventional welding techniques directly connect a torch to a power source, plasma arc welding uses a control console between the two.

Some of the console features are the torch protection circuit, high-frequency arc starting unit, power supply for the pilot arc, water, and gas valves, individual meters for plasma, and shielding gas flows.

Power supply

Plasma arc welding uses DC power (rectifiers or generators) of at least 70 volts for open circuit voltage with drooping characteristics to have greater control in generating weld beads.

Gases used

  • Plasma gas – exits the constricting nozzle separately from the shielding gas envelope and becomes ionised

  • Shielding gases (argon, helium, hydrogen) – inert gas protects the weld from the atmosphere

  • Back-purge and trailing gas – certain materials require special conditions

Wire feeder

Plasma welding may use wire feeders with a constant velocity that can be modified to run from 254 mm per minute to 3180 mm per minute.

Applications

Steel tubes

PAW is a great welding method in manufacturing steel tubes as it can be performed at high-speed welding with great metal penetration. Some industries prefer the plasma welding process to conventional TIG since its system is faster and uses less filler material.

Electronics

One of the welding parameters of the plasma welding process is it can run at low current modes. This mode allows small metal component welding, which deals with delicate materials sensitive to environmental factors.

Medical industry

Medical devices require precise components in order to run effectively. PAW is perfect for welding these components as it can reliably create a consistent weld bead.

Advantages of Plasma Welding

  1. Can be operated in every welding position.

  2. Fast travel speeds from concentrated heat input.

  3. Keyhole welding allows for complete penetration.

  4. Low current mode is suitable for thin and sensitive components.

Disadvantages of Plasma Welding

  1. Expensive equipment and components.

  2. Requires training and skill to create good welds.

  3. Produces 100dB noise.

  4. Creates ultraviolet and infrared radiation.

  5. Water cooling is necessary because of high working temperatures.

  6. Delicate equipment needs a higher amount of maintenance.

Nov 27
0

Pricing for Inventor Documents Now Obtainable

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13.10.2022 by Siim Sild

In addition to the aid for SolidWorks documents we additional before this calendar year, we’re now ready to quote file sorts native to Autodesk Inventor as properly.

The listing of file sorts our platform can now quotation is as follows:

  • .ipt – Inventor section file
  • .sldprt – SolidWorks aspect file
  • .stp – the universal 3D CAD file 
  • .dxf –  2D drawing file (can quotation flat laser reducing work opportunities)
no price difference
.stp or .ipt, no change in pricing

So as you can see from the screenshot above, there is no require to commit time changing the files to .stp when using Inventor from now on. 

Nov 24
0

Sheet Metal Hemming | Hem Types & Processes Explained

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Hemming is a common metalworking process mainly carried out to reinforce an edge, hide burrs or just improve the overall appearance of sheet metal parts. When hemming is carried out in a way that a joint between two sheet metal parts is created, it is called seaming but more on that later.

So, without further ado, let’s dive into the subject.

What Is Sheet Metal Hemming?

Hemming in sheet metal operations refers to the bending of a sheet metal edge onto itself. It is very similar to edge stitching in clothes. Similar to how an edge stitch strengthens the edge and makes it more durable, a hem imparts strength to the metal edge and improves its appearance. The edge of one part may also be folded onto another part to create a joint.

Hemming is usually done in two stages. The first stage creates an acute bend using acute tooling (V die) followed by a flattening of the return flange using a flattening die.

A complete list of hemming benefits on a sheet metal product is as follows:

  • Hems strengthen the sheet metal edge

  • They improve the surface appearance and surface quality

  • They hide defects such as rough edges and burrs

  • They can connect parts

  • They make the edges safer to handle

Hem Types

The different sheet metal hems based on the hem shape are as follows:

  • Flat or closed hem

  • Open hem

  • Teardrop hem

  • Rope hem

  • Rolled hem

Flat or closed hem

In a flat or closed hem, the part of the edge that bends sits completely flush over the rest of the metal sheet. The angle between the returning flange and the sheet metal is 180 degrees. The inside radius is zero and thus, there is no gap between the returning flange and the metal sheet.

Closed hems require a lot more power and tonnage from the presses than open or teardrop hems and it is also not advised for metal sheets that are over 2-3mm in thickness since the sheets are likely to fracture. 

Open hem

Sheet metal hemming types - open hem

In an open hem, the returning flange is folded over the sheet metal but there remains an air pocket between the two. The bend angle in this hem type is also 180 degrees.

Teardrop hem

Sheet metal hemming types - teardrop hem

In a teardrop hem, the returning flange is bent beyond 180 degrees. The resulting shape resembles a teardrop.

It is perfect for materials that do not have the required ductility to provide closed hems. Teardrop hems are used for fragile materials such as aluminium.

Rope hem

Sheet metal hemming types - rope hem

A rope hem has a returning flange at a bent of more than 180 degrees. Once the hem achieves the shape of an open hem, the returning flange is pressed onto the part surface through a flattening die.

The edge is bent in shape similar to an open hem and then the second piece to be connected is inserted into the gap between the metal sheet and the returning flange. Further pressing takes place making the second parts sit flush between the metal sheet and the returning flange and create a joint.

Rolled hem

Sheet metal hemming types - roller hem or curl

In a rolled hem, the bent portion of the sheet metal is tucked back into itself.  This creates smooth round edges all around for holding the part from the hemmed edges. This process is also commonly referred to as curling.

Hemming Process

The hemming process can be carried out in one of the following two ways:

  • Die hemming process

  • Roller hemming process

Die Hemming Process



Die hemming process


Die hemming process

Die hemming is the conventional hemming operation that uses a die and press to carry out hemming. In this process, the bending occurs along the full length at predefined angles in multiple steps. These steps are known as pre-hemming and final hemming.

For instance, when forming a closed hem, the edge will be bent to 45 degrees in the first step by passing it through a press brake. The next bent occurs by means of the same press brake but a different part of the tool that completes the closed hem.

The die hemming process is not very flexible and is generally restricted to the production of flat, uncomplicated panels. The investment in the equipment is high but the cycle times can be brought down to be quite low.

Roller Hemming Process



Manual Roller Hemming


Manual Roller Hemming

The Roller hemming process was invented to increase the flexibility of the hemming operation. It generally uses robots to control rollers that bend the edges but there are simpler manual roller hemming machines available that can handle only simpler tasks with less accuracy. The rollers travel along the edges and bend the part edge to the desired angle in multiple steps.

The orientation of the sheet may be changed multiple times during the hemming process to reduce the travel of the roller and increase the cycle time. Apart from the robot itself, this method is considered economical both for low and high-volume tasks. Robot roller hemming allows for jumping back on forth between producing different parts through quick program changes.



Robotic Roller Hemming


Robotic Roller Hemming

Hemming and Seaming Difference

A seam is used to connect two metal parts by interlocking the edges of the folded sheet metal parts. The resulting shape may even form a seal that isolates one side of the sheets from the other.

As a result, seaming finds use in sealing canned goods in the food industry. Hemming and seaming come across as very similar processes but there are some key differences.

These differences are as follows:

  1. A hem’s return flange sits flush on the metal sheet in some cases but in seaming, the return flange never sits flush. There is always some gap.

  2. A hem’s primary purpose is to reinforce the edges and improve the appearance. In seaming, the primary purpose is to connect two parts.

  3. A seam may be used to seal one end of the two sheet metals when joined as seen in canned goods. A hem is never used for this purpose.

  4. They are both used in different applications. Hemming finds use in automotive and aerospace industries but is also suitable for a lot of general applications. Seaming typically finds use in the food industry, metal roofing, and the automotive industry to some extent.

Nov 18
0

Maintaining emergency blood supplies safe and sound on blood bikes

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Shropshire, Dublin and Cheshire Blood Bikes supply urgent provides to medical options throughout the 3 counties and over and above.

Typically relied on in occasions of unexpected emergency, they can give anything from breast milk for neonatal models to urgent supplies of blood or platelets when hospitals are managing low. The assistance is entirely manned by volunteers, and the team’s 16 motorbikes are a lifeline for its users, masking 350,000 miles a yr to assistance men and women in will need.

Exceptional remedy 

When the charity updated their fleet, they needed help to configure a expert tray which could be fitted to the back again of every bike to transportation the a lot-required blood packing containers and containers necessary for deliveries.

Alpha Producing designed a specialist modular tray with various repairing kits to in good shape various designs of bicycle, together with the charity’s new BMW and Moto Guzzi products.

“It really has manufactured a difference”, claims Fleet Supervisor Nigel Howells. “We now have a program that can work with any bike we pick out. It can be adapted and remodelled as desired to supply a easy alternative which can even transportation two unique products at the exact same time.”

Collaborative method

The HEX Group’s know-how in graphics meant they were also equipped to source and implement specialist motorbike livery that correctly match the charity’s new BMW and Moto Guzzi models.

Getting apparent signage on their fleet of motorbikes is important in earning confident riders are seen on the road and can be safely and securely recognized.

“Our 160 volunteer riders count on clear signage on the Blood Bikes to hold them risk-free and make them obvious on the highway,” provides Nigel.

“When we had to adjust bike styles, it was hard to obtain a provider who could provide the livery required. Functioning with HEX Graphics has created the full course of action easier, and we can now quickly and simply model up new bikes so our riders can continue to get out on the roads delivering the a great deal-required help to the NHS.”

Updating 8 new bikes and with one more a few in the pipeline, the Group is hoping the notion will turn into greatest observe in serving to other Blood Bicycle teams across the country delivering a very simple resolution to continue to keep volunteer riders protected on the street.

Nov 15
0

Laser Welding Described | Laser Beam Welding

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Laser welding takes advantage of a higher-precision laser beam to fuse metals and thermoplastics. The accuracy and precision of the system produces minimal thermal distortion, creating it excellent for welding delicate resources. The course of action is most generally automated, allowing for for substantial welding costs.

Let’s dive deeper into the strategy at the rear of laser welding.

What Is Laser Welding?

Laser welding or laser beam welding (LBW) is a method that employs a concentrated warmth resource in the form of a laser to melt the supplies, which fuse alongside one another as they neat down. It is a functional course of action considering that it can weld slim products at immediate welding speeds even though operating slim and deep welds for thicker products.

Though laser welding machines expenses much more than traditional welding processes, its working expenditures are lessen considering that it doesn’t necessarily have to have added filler material and publish-processing. Also, the higher welding speeds permit the generation of extra parts for each hour. The know-how guiding this process distinguishes significantly from typical arc welding procedures these as MIG and TIG. Contemporary laser welding apps use programmable robots included with sophisticated optics to exactly target an location in the workpiece.

Styles of Laser Beam Welding

There are two different varieties of laser beam welding, both of those with distinctive operating principles to fit specific programs. The way that the materials interacts relies upon on the laser beam’s electricity density.

Heat Conduction Welding

In this strategy, a targeted laser beam is used to melt the area of the foundation products. When the joint solidifies, a specific and smooth weld seam is produced. Welds developed applying the head conduction system do not usually need any supplemental finishing, the top quality is fantastic “out of the box”.

The electricity enters the weld zone only by warmth conduction. This restrictions the welding depth and as a result the approach is excellent for joining slender supplies. Heat conduction welding is frequently made use of for noticeable weld seams which want to be aesthetically satisfying.

There are two subcategories of heat conduction welding:

  • Direct heating – the laser beam immediately applies its electric power on the area of the metals.

  • Electrical power transmission – absorbing ink is utilized to the joint, soaking up the vitality that the laser beam applies.

Deep Penetration/Keyhole Welding

Working the course of action in keyhole welding (deep penetration) method generates deep, slim welds with uniform construction. For metals, energy densities of about 1 megawatt for every sq. centimetre are utilized. This does not only soften the metal but vapourises it, generating a slim vapour-loaded cavity.

This is termed a keyhole cavity or vapour capillary and is loaded with molten metal as the laser beam advances by the workpiece. Keyhole welding is a higher-speed system and consequently, the distortion and the formation of a warmth-affected zone are retained to a minimum.

Laser Beam Welding Course of action




Automatic Laser Welding

Laser beam welding is effective on the basic principle of using a laser with significant ability density to utilize warmth to a joint in between the surface of two metals. The substance melts at the joint, and it permits fusion between the metals as it solidifies.

Laser welding is generally carried out by welding robots that can specifically utilize a big amount of money of vitality at significant speeds, guided by versatile optical fibres. This benefits in melting a sufficient total of metal in the joint, creating slim welds with small distortion. Handheld laser welding programs seemingly provide a good choice to bulky industrial devices, but these welders’ safety is staying questioned.

The welding approach can be done below atmospheric situations but for more reactive products inert gasoline shielding is suggested to get rid of the threat of contamination. Likewise to electron beam welding, laser welding could be carried out in a vacuum but it is not deemed economically possible. Thus, laser welders occur equipped with gas nozzles that offer inert gasoline to the weld region.

Numerous laser welding programs are carried out with out the need to have for extra filler materials. Even so, some demanding components and programs demand filler product to generate satisfactory welds. Incorporating filler substance enhances the weld profile, lessens solidification cracking, presents the weld improved mechanical houses and allows for extra exact joint fit-up. The filler material can arrive in powder variety or as filler wire but considering that powders are commonly far more costly for most materials, using wire feedstock is a lot more widespread.

The four most popular joint types utlised by laser welding are butt welds, edge flange welds, filler lap welds and overlap welds.

Laser welding can be carried out on a wide range of metallic components which includes low-carbon steel, stainless steel, aluminium, titanium, etcetera. It can also fuse components that aren’t as prevalent as the aforementioned, such as Kovar and substance combinations deemed not uncomplicated to weld these kinds of as copper-copper, copper-aluminium, etc. Welding substantial-carbon steels is normally not advisable owing to the higher cooling rate which tends to bring about cracks. 

Types of Lasers

There are three major styles of laser welders utilised for the welding process:

Gasoline laser (CO2)

A CO2 laser resource is a combination of gases with CO2 currently being the primary element along with nitrogen and helium. These lasers can function in a continuous or pulsed mode at a reduced present-day and large voltage to excite the gasoline molecules. Carbon dioxide lasers are also utilized in unique circumstances, this sort of as in twin-beam laser welding, whereby two beams are developed and arranged possibly in tandem or facet-by-facet.

Strong-condition laser

Stable-point out lasers use Diode Pumped Good Point out (DPSS) technologies to pump ore these kinds of as ruby, glass or yttrium, aluminium, and garnet (YAG), or yttrium vanadate crystal (YVO4) with a laser diode to develop laser rays. These lasers are operated in possibly continuous wave or pulsed beam method. The pulsed manner provides joints equivalent to location welds but with comprehensive penetration. These lasers have their truthful share of negatives when when compared to modern fibre lasers but we just can’t deny that good-point out lasers nevertheless have fantastic beam stability and top quality together with significant effectiveness.

Semiconductor-based mostly lasers are also in the stable point out but are normally deemed a separate course from strong-state lasers. These lasers are only employed for much less expensive and small projects. But they’re from time to time applied when welding in tricky-to-access areas given that the tools is far more compact. The top quality of the beam is considerably even worse when in contrast to other types of lasers and hence, it is not as frequent in industrial configurations.

Fibre laser

Fibre lasers are the newer type of good-condition lasers that offer you a lot more electricity, much better good quality and safer procedure. In fibre lasers, the laser beam is established when the fibre absorbs raw light from the pump laser diodes. To accomplish this transformation, the optical fibre is doped with a unusual-earth factor. By utilizing distinctive doping features, laser beams with a extensive vary of wavelengths can be designed and this tends to make fibre lasers ideal for a wide variety of programs, including laser welding and laser slicing. While, it’s really worth noting that a typical laser slicing head can not be utilised for welding and a laser welding head can not fulfill the reducing speeds and good quality demanded in most industrial applications.

Benefits of Laser Welding

  • Wonderful quality thanks to lower warmth enter and precise laser power regulate.

  • The system is quickly which allows for small device expenditures.

  • Good welding depth resulting in superior-toughness welds.

  • Makes it possible for welding content mixtures that other solutions can not be part of.

  • The easy welding machines will allow welding below special situations.

Down sides of Laser Welding

  • Significant first investment

  • Stringent tolerances involve ideal workpiece assembly and laser calibration.

  • Components with high reflectivity and conductivity (aluminium and copper) can produce a fussy weld final result (in the circumstance of Co2 lasers).

  • Porosity and brittleness could possibly final result from quick solidification.

  • Laser optics are rather delicate and can simply be damaged.

Laser-Hybrid Welding

Laser-hybrid welding brings together the concepts of electric arc and laser beam. The two concurrently act in the very same welding zone, complimenting every other and developing a unique welding procedure. Despite the fact that laser welding can be applied in conjunction with virtually any arc welding course of action, there are some that stand out and are utilised far more generally.

There are 3 primary varieties of laser-hybrid welding:

The hybrid welding procedure gives deep penetration introduced by laser welding and a weld cap profile obtained similar to arc welding processes. Using protecting shielding gases and other arc welding consumables offer increased command about the weld characteristics than laser welding would make it possible for just by by itself. Laser-hybrid welding is absolutely a procedure that is on the rise and will be utilised additional and more in the shipbuilding, railroad, automotive industries and substantial-scale pipe welding jobs in the future.

Nov 03
0

Satisfy the Team – Libby Mellor, Trainee Good quality Engineer

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Twelve months soon after signing up for Alpha Production, following attending the Company’s very first recruitment open working day, Libby Mellor, a previous Mechanical Engineering apprentice, has executed the iAuditor excellent handle processes at the new 35,000sq ft Alpha Production Chemical Systems web site in Stafford.

Libby joined the business as a Trainee Good quality Engineer and explains how she founded an desire in High quality Handle from her Engineering Apprenticeship Programme: “Spending time in numerous departments gave me a authentic perception into Engineering. Top quality was the 1 region that significantly captured my interest, realising the importance of inspecting and monitoring operations to guarantee they meet up with production standards.”

Not long into her position, Libby embarked on the problem of utilizing the iAuditor top quality inspection procedure at our new Stafford web-site in conjunction with INEOS Electrochemical Solutions. Functioning in a manufacturer-new manufacturing unit, Libby clarifies how she tackled the challenge head-on:

“It was good that Alpha saw my potential and gave me this option. In the commencing, the integration of the INEOS regulate program into iAuditor was a priority, regularly highlighting prospective adjustments and addressing them together the way. Manufacturing of the solution experienced not however begun, which intended doing work intently with INEOS was important, and ISIRs (Original Sample Inspection Stories) were being important to making sure top quality specifications were being achieved. Right before manufacturing commenced, the top quality handle process of normal inspections was essential to reaching this kind of superior-precision engineering.

“We have occur a very long way, and my day-to-day regimen focuses largely on operator instruction and making certain all the good quality controls we have set in location are adhered to. The iAuditor software package is tablet-centered and keeps inspections exact and up-to-date, and the method is easy and quick.”

As soon as the new website is completely commissioned and handed in excess of, Libby will return to the High-quality Department at Alpha, exactly where she has not long ago been acknowledged on to the Group’s new Leadership Programme, alongside a High quality Administration and Auditing course. Libby’s commitment and enthusiasm for her function and the business are unquestionable, and her upcoming at Alpha is interesting.

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