2 1/4Cr-1Mo鋼溶接金属の靱性と焼もどし脆化

Improvement of toughness at low temperature in Cr-Mo weld metal is one of the most important problems. Welding materials which could satisfied rather high toughness after step cooling had been developed. In order to obtain much improved toughness, further fundamental studies on the submerged arc weld metal in 2 1/4Cr-1Mo steel have been carried out.Effect of chemical compositions on weld metal toughness after stress relief treatment and step cooling were investigated. As the result, it could be possible to reduce temper embrittlement and to obtain high toughness at low temperature by means of lowering Si, P and oxygen content as well as controlling C content in weld metal. These optimum chemical composition coud be obtained by welding materials which are combination on solid wire and highly basic bonded flux.