钢轧辊修复焊缝中残余奥氏体的存在形态及其影响

在９Ｃｒ２Ｍｏ轧辊局部冷焊焊缝中，研究了焊缝服役后的疲劳现象与残余奥氏体（ＡＲ）数量、形态的关系．结果表明：块状ＡＲ是焊缝早期疲劳的主要原因；其疲劳机制是块状ＡＲ塑变切断破坏和高应力诱发相变孪晶．强碳化物形成元素与Ｃ符合定比规律后，固溶入基体的弱、非碳化物元素影响着ＡＲ的数量和形态．薄膜状ＡＲ与板条马氏体（ＭＬ）形成的ＭＬ／ＡＲ束，可显著提高冷轧抗疲劳性．

INFLUENCE OF RESIDUAL AUSTENITE (A R) FOR ANTI FATIGUE ABILITY IN THE PARTIAL COLD WELDED METAL ON THE COLD WORK ROLLER

The relation between fatigue of the used weld metal and the quantity and morphology of residual austenite (A R) is studied in the partial cold welded metal on the 9Cr2Mo steel roll. Test result indicated that the block like A R was the main cause of early stage crack of the weld metal. The crack mechanism was the block like A R fractured by plastic deformation and because of phase change twinning by high stress. As the quantity of strong carbide elements and carbon element accorded with the fixed ratio theorem, the feeble carbide elements and non carbide elements which dissolved in base phase affected the quantity and morphology of A R. M L/A R phase which was formed from thin film like A R and low carbon martensite can improve the anti fatigue ability remarkably.