Watch this video for an overview of the features…
WeldTech has released an informative demonstration video that showcases the WT3500 PTA Controller utilized in a PTA work cell application. In the video, WeldTech‘s Plasma Transferred Arc System performs welding examples for Hard Banding, Linear, Outer Diameter (OD) as well as an Inner Diameter (ID) weld where a .100 inch deposit is made in a bore opening a mere 1.5 inches in diameter.
PTA systems have changed a bit over the years
Layer limits are most common with carbide-based products such as chromium carbide and tungsten carbide. Martensitic and austenitic hardfacing products can often be applied in additional layers unless the manufacturer specifies a limit.
Because metal carbide deposits are comparatively brittle, repeated layers can increase internal stress. Stress may concentrate at the roots of check cracks until separation or spalling occurs between the base metal, buffer layer, and hardfacing deposit.
Carbon steels and low-alloy steels containing less than 1% carbon are commonly hardfaced. Higher-carbon alloys may need a buffer layer before the wear-resistant overlay is applied.
Materials that can often be hardfaced include:
Cobalt-based hardfacing alloys contain multiple carbide types and are often selected for severe abrasion at elevated temperatures. They may also provide corrosion resistance in certain service environments. Deposit hardness commonly ranges from 25 HRC to 55 HRC, and work-hardening versions are available.
Nickel-based hardfacing alloys may contain chromium borides for abrasion resistance. They are often considered when the application involves abrasion along with high temperature, corrosive atmospheres, or both.
In plasma transferred arc welding, hardfacing applications typically aim for low penetration and low dilution. Pure argon or argon-hydrogen blends are commonly used to help achieve those results.
Chromium carbide hardfacing generally refers to iron-based alloys with high chromium content, typically above 18%, and high carbon content, typically above 3%. These elements combine to form hard chromium carbides that improve abrasion resistance. Chromium carbide overlays often develop stress-relieving check cracks about every 1/2 inch and can also offer favorable slip characteristics because of their low coefficient of friction.
As chromium and carbon levels increase, abrasion resistance generally improves, with carbon having the strongest influence. Typical hardness values range from 40 HRC to 65 HRC. Some formulations include additional carbide- or boride-forming elements for improved wear resistance at elevated temperatures. Many chromium carbide products are limited to two or three layers.
Layer limits are most common with carbide-based products such as chromium carbide and tungsten carbide. Martensitic and austenitic hardfacing products can often be applied in additional layers unless the manufacturer specifies a limit.
Because metal carbide deposits are comparatively brittle, repeated layers can increase internal stress. Stress may concentrate at the roots of check cracks until separation or spalling occurs between the base metal, buffer layer, and hardfacing deposit.
Carbon steels and low-alloy steels containing less than 1% carbon are commonly hardfaced. Higher-carbon alloys may need a buffer layer before the wear-resistant overlay is applied.
Materials that can often be hardfaced include:
Cobalt-based hardfacing alloys contain multiple carbide types and are often selected for severe abrasion at elevated temperatures. They may also provide corrosion resistance in certain service environments. Deposit hardness commonly ranges from 25 HRC to 55 HRC, and work-hardening versions are available.
Nickel-based hardfacing alloys may contain chromium borides for abrasion resistance. They are often considered when the application involves abrasion along with high temperature, corrosive atmospheres, or both.
In plasma transferred arc welding, hardfacing applications typically aim for low penetration and low dilution. Pure argon or argon-hydrogen blends are commonly used to help achieve those results.
Chromium carbide hardfacing generally refers to iron-based alloys with high chromium content, typically above 18%, and high carbon content, typically above 3%. These elements combine to form hard chromium carbides that improve abrasion resistance. Chromium carbide overlays often develop stress-relieving check cracks about every 1/2 inch and can also offer favorable slip characteristics because of their low coefficient of friction.
As chromium and carbon levels increase, abrasion resistance generally improves, with carbon having the strongest influence. Typical hardness values range from 40 HRC to 65 HRC. Some formulations include additional carbide- or boride-forming elements for improved wear resistance at elevated temperatures. Many chromium carbide products are limited to two or three layers.
Limited-layer products usually are in the metal carbide families, such as chromium carbide and tungsten carbide. You can apply martensitic and austenitic products in unlimited layers unless the manufacturer specifies otherwise.
The brittle nature of the metal carbides leads to check-cracking, and as multiple layers are applied, stress continues to build, concentrating at the root of the check cracks, until separation or spalling occurs between the parent metal or buffer and the hard-facing deposit.
Cobalt alloys contain many types of carbides and are good for severe abrasion at high temperatures. They also have good corrosion resistance for some applications. Deposit hardness ranges from 25 HRC to 55 HRC. Work-hardening alloys also are available.
Nickel-base alloys can contain chromium borides that resist abrasion. They can be good particularly in corrosive atmospheres and high temperatures when abrasion is a problem.
Low penetration and dilution are the major objectives in hard-facing, so pure argon and mixtures of argon with hydrogen generally will produce the desired result.
These alloys often resemble the parent metal alloy and are applied to severely worn parts to bring them back to dimension or act as a buffer for subsequent layers of a more wear-resistant hard-facing deposit. If the hard-facing produces check cracks, then it’s wise to use a tough manganese product as the buffer to blunt and stop the check cracks from penetrating into the base metal
Metal parts often fail their intended use not because they fracture, but because they wear, which causes them to lose dimension and functionality. Hard-facing, also known as hard-surfacing, is the application of buildup or wear-resistant weld metals to a part’s surface by means of welding or joining.
Layer limits are most common with carbide-based products such as chromium carbide and tungsten carbide. Martensitic and austenitic hardfacing products can often be applied in additional layers unless the manufacturer specifies a limit.
Because metal carbide deposits are comparatively brittle, repeated layers can increase internal stress. Stress may concentrate at the roots of check cracks until separation or spalling occurs between the base metal, buffer layer, and hardfacing deposit.
Carbon steels and low-alloy steels containing less than 1% carbon are commonly hardfaced. Higher-carbon alloys may need a buffer layer before the wear-resistant overlay is applied.
Materials that can often be hardfaced include:
Cobalt-based hardfacing alloys contain multiple carbide types and are often selected for severe abrasion at elevated temperatures. They may also provide corrosion resistance in certain service environments. Deposit hardness commonly ranges from 25 HRC to 55 HRC, and work-hardening versions are available.
Nickel-based hardfacing alloys may contain chromium borides for abrasion resistance. They are often considered when the application involves abrasion along with high temperature, corrosive atmospheres, or both.
In plasma transferred arc welding, hardfacing applications typically aim for low penetration and low dilution. Pure argon or argon-hydrogen blends are commonly used to help achieve those results.
Chromium carbide hardfacing generally refers to iron-based alloys with high chromium content, typically above 18%, and high carbon content, typically above 3%. These elements combine to form hard chromium carbides that improve abrasion resistance. Chromium carbide overlays often develop stress-relieving check cracks about every 1/2 inch and can also offer favorable slip characteristics because of their low coefficient of friction.
As chromium and carbon levels increase, abrasion resistance generally improves, with carbon having the strongest influence. Typical hardness values range from 40 HRC to 65 HRC. Some formulations include additional carbide- or boride-forming elements for improved wear resistance at elevated temperatures. Many chromium carbide products are limited to two or three layers.
Hardfacing is a proven way to extend the service life of industrial components exposed to abrasion, impact, heat, corrosion, and metal-to-metal wear. This FAQ explains how wear-resistant weld overlays, PTA hardfacing, chromium carbide coatings, buildup alloys, and base-metal preparation work together to restore worn parts, reduce downtime, and improve equipment reliability.
Layer limits are most common with carbide-based products such as chromium carbide and tungsten carbide. Martensitic and austenitic hardfacing products can often be applied in additional layers unless the manufacturer specifies a limit.
Because metal carbide deposits are comparatively brittle, repeated layers can increase internal stress. Stress may concentrate at the roots of check cracks until separation or spalling occurs between the base metal, buffer layer, and hardfacing deposit.
Carbon steels and low-alloy steels containing less than 1% carbon are commonly hardfaced. Higher-carbon alloys may need a buffer layer before the wear-resistant overlay is applied.
Materials that can often be hardfaced include:
Cobalt-based hardfacing alloys contain multiple carbide types and are often selected for severe abrasion at elevated temperatures. They may also provide corrosion resistance in certain service environments. Deposit hardness commonly ranges from 25 HRC to 55 HRC, and work-hardening versions are available.
Nickel-based hardfacing alloys may contain chromium borides for abrasion resistance. They are often considered when the application involves abrasion along with high temperature, corrosive atmospheres, or both.
In plasma transferred arc welding, hardfacing applications typically aim for low penetration and low dilution. Pure argon or argon-hydrogen blends are commonly used to help achieve those results.
Chromium carbide hardfacing generally refers to iron-based alloys with high chromium content, typically above 18%, and high carbon content, typically above 3%. These elements combine to form hard chromium carbides that improve abrasion resistance. Chromium carbide overlays often develop stress-relieving check cracks about every 1/2 inch and can also offer favorable slip characteristics because of their low coefficient of friction.
As chromium and carbon levels increase, abrasion resistance generally improves, with carbon having the strongest influence. Typical hardness values range from 40 HRC to 65 HRC. Some formulations include additional carbide- or boride-forming elements for improved wear resistance at elevated temperatures. Many chromium carbide products are limited to two or three layers.
