PTA

PTA Welding Surface Solutions

PTA welding has many benefits as a hardfacing process where a metallurgical bond is necessary. It can handle abrasion better than most thermal spray coating processes and can be built up much thicker. The metallurgical bond also allows it to operate in environments where impact damage is likely to occur.

How it works

Plasma transferred arc welding uses a tungsten electrode and the workpiece as the anode to create and transfer a plasma arc inside a stream of ionized gas. This reaction creates heat and a plasma state that can melt and apply metallic materials to other metal surfaces at temperatures up to 23,000 F. The heat energy of the constricted arc creates deeper weld penetration in a narrower field. This reduces the heat affected zone, increases welding speed over TIG and MIG, and creates an incredibly stable arc for precise surface coatings.

Advantages

• Metallurgical bond for hardfacing where a strong bond is necessary
• Handles abrasion better than most thermal spray coating processes
• Can be built up much thicker than most thermal spray coatings
• Operates where impact damage is likely to occur
• Deeper weld penetration in a narrower field
• Reduced heat affected zone (HAZ) versus traditional welding
• Faster welding speed than TIG and MIG
• Incredibly stable arc for precise surface coatings

Common applications

• Valve stems and seats
• Auger flights and large screw flights
• Pump components
• Direct impact cutting tools

Common PTA Weld Hardfacing Materials

• Nickel-based alloys in the Colmonoy product line (Colmonoy 6, 56, 69, 88, and more)
• Cobalt-based alloys in the Stellite and Wallex product lines (Stellite 1, 6, 12, Wallex 50, and more)
• Tungsten carbides (Wallex 55, Colmonoy 75, Colmonoy 635)
• Stainless steels

PTA Hardfacing Properties