HAYNES282 high-temperature nickel-base alloy pipe welding technology

Abstract

The invention relates to a HAYNES 282 high-temperature nickel-base alloy pipe welding technology. When a current HAYNES 282 straight pipe is lengthened and welded, due to continuous welding, the interlayer temperature cannot be controlled, heat input is large, the tendency of heat crack generation is increased, if only reduction of welding current and voltage is adopted for reducing welding heat input and the arc stopping temperature controlling manner is used for reducing the interlayer temperature, the welding efficiency can be reduced, and no welding technology for HAYNES 282 nickel-base alloy small-caliber pipes exists at home and abroad. The specific welding technology comprises the following steps that in the welding process, the interlayer temperature is controlled to be not largerthan 150 DEG C, a spraying device can be adopted for conducting interlayer temperature control in a spraying cooling manner in the heating wire argon tungsten-arc welding process, and when bottoming layers are welded and pipes rotate to 270 degrees, a cooling water valve is opened, and the spraying device is adopted for spraying and cooling on a welding connector till welding of all bottoming layers, filling layers and face covering layers is finished. The technology is used for welding the HAYNES 282 high-temperature nickel-base alloy pipes.

Description

Technical field: [0001] The invention relates to a HAYNES 282 high-temperature nickel-based alloy pipe welding process. Background technique: [0002] At present, when HAYNES 282 straight pipes are connected by hot wire mechanical tungsten argon arc welding, due to continuous welding, the interlayer temperature cannot be controlled, and the heat input is relatively large, which increases the tendency of thermal cracks, and the welding interlayer temperature can reach 500 °C Above, if only reduce the interlayer temperature by reducing the welding current, voltage, welding heat input and arc stop temperature control, the welding efficiency will be reduced. There is no welding process for HAYNES 282 nickel-based alloy small-diameter pipes at home and abroad. ; [0003] HAYNES 282 is an aging-strengthened high-temperature nickel-based alloy with a chemical composition of 57Ni-20Cr-10Co-8.5Mo-Al-Ti. Due to its excellent high-temperature mechanical properties, corrosion resistanc...

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Problems solved by technology

[0002] At present, when HAYNES 282 straight pipes are connected by hot wire mechanical tungsten argon arc welding, due to continuous welding, the interlayer temperature cannot be controlled, and the heat input is relatively large, which increases the tendency of thermal cracks, and the welding interlayer temperature can reach 500 °C Above, if only reduce the interlayer temperature by reducing the welding current, voltage, welding heat input and arc stop temperature control, the welding efficiency will be reduced. There is no welding process for HAYNES 282 nickel-based alloy small-diameter pipes at home and abroad. ;

[0003] HAYNES 282 is an aging-strengthened high-temperature nickel-based alloy with a chemical composition of 57Ni-20Cr-10Co-8.5Mo-Al-Ti. Due to its excellent high-temperature mechanical properties, corrosion resistance, and easy processing performance, it has become a 700°C alloy at present. Candidate materials for advanced ultra-supercritical boilers, HAYNES 282, due to the segregation of trace elements and the formation of eutectics with a low melting point during welding, are easily pulled to form thermal cracks under the action of welding stress, and the metal fluidity of nickel-based alloys is poor during welding , it is very easy to produce unfused and incomplete defects. In addition, when nickel-based alloys are welded, dense oxide films are easy to form between layers. Due to the high melting point of the oxide film, inclusion defects will be generated in the weld

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