摩托车主副轴冷挤压模具早期失效原因分析

Cr12MoV属高碳高合金钢，强度较高，热塑变形抗力较大，变形温度区狭窄，易锻裂。锻造时要严格控制锻造温度，温度下降时立即返炉；锻打时严格执行“轻-重-轻”规律不宜过重，避免锻造变形时产生裂纹形成裂纹源；棱角要轻击倒平，避免温差和附加应力引起角裂；锻造过程中要注意观察，镦斜、拔歪要及时纠正，发现裂纹要立即去除消除裂纹源。

An Analysis of the Cause Leading to Earlier Failures of Cold Extrusion Dies for Motorcycle Main Shaft and Countershaft

Cr12MoV,a kind of high-carbon alloy steel,is higher in strength,larger in resistance to thermoplastic deformation,narrow in terms of deformation temperature zone and easy in fracture when forged.When forging,the temperature should be strictly controlled and the forged piece should be immediately refurnaced when forging temperature drops;the principle of"gently-heavily-gently"should be strictly followed during forging.Over heavily is not acceptable;the formation of crack source should be avoided when deforma...