A classification

Heat resistant steel is widely used in electric power, power engineering, petrochemical and other industries, commonly used Cr Mo and Mn Mo type heat-resistant steel and Cr Mo based multi-element alloy heat-resistant steel.

II. Weldability analysis

The main problems of weldability of heat-resistant steel are hardening, cold cracking, softening in heat affected zone and reheat cracking in post weld heat treatment or long-term use at high temperature. Heat resistant steel is generally welded in the state of heat treatment (normalizing and tempering or quenching and tempering). Most of the heat-resistant steel is subject to high temperature tempering after welding.

III. welding process

Preheating shall be carried out before tack welding and formal welding. If the weldment is rigid, preheating shall be carried out as a whole.