Cr7Mo3V2Si钢表面改性复合强韧化工艺研究

Study of Surface Modification-Composite Strengthening and toughening Heat Treatment of Steel Cr7Mo3V2Si

研究了预渗氮和预渗碳对 Cr7Mo3V2Si 钢经强韧化处理后所得渗层的扫描断口形态、冲击韧性和硬度分布的影响.结果表明,Cr7Mo3V2Si 钢的含氮马氏体具有高碳马氏体形态和孪晶亚结构.渗层出现硬度峰值,表面硬度略低,表面硬度受控于残余奥氏体量,可通过冷处理而得到提高.建议对 Cr7Mo3V2Si 钢制冷作模具采用表面改性复合强韧化工艺,以提高使用寿命和改善其破坏形式.

Sludies the influence of prenitriding and precarburizing on morphology of scanning fracture surface,im- pact ductility and hardness distribution of nitrided case and carburized layer of steel Cr7Mo3V2Si after strengtheming and toughening heat treatment.The results show that the martensite containing nitrogen of steel Cr7Mo3V2Si has same morphology with high carbon martensite and has twining substructure.A peak hardness ap- peared in the hardness curve of nitrided case.The hardness near surface is lower and depends on amount of residual austenite,so may be increased by cold treatment The auhors propose that the surface modification -composite strengtheming and toughening heat treatment should be used for cold working dies made of steel Cr7Mo3V2Si in order to increase the service life and improve the destructive type.