40Cr钢行星架盲孔台阶纵向裂纹形成原因分析  

Reason analysis of longitudinal cracks on the inter wall of 40Cr steel stuff canister

作　　者：杨光华 YANG Guanghua(Ningbo Jinjiu Technology Co.,Ltd.,Ningbo 315480,Zhejiang,China)

机构地区：[1]宁波津玫科技有限公司,浙江宁波315480

出　　处：《金属加工（热加工）》2024年第4期47-51,共5页MW Metal Forming

摘　　要：采用宏观分析、化学成分分析、金相检测及能谱分析等方法,对40Cr钢行星架盲孔台阶纵向裂纹性质及形成原因进行了分析。结果表明:40Cr钢行星架盲孔台阶纵向裂纹属于淬火裂纹,其产生原因是由于行星架的形状而使其淬火时内外马氏体转变的冷却不等时性,以致盲孔台阶处形成组织应力型的淬火残余应力,呈局部切向拉应力,当局部切向拉应力值大于马氏体的断裂强度时,则发生淬火开裂。The longitudinal cracks on the blind hole step of 40Cr steel planetary carrier was analyzed by means of macroscopic crack analysis,chemical composition analysis,metallographic examination and energy spectrum analysis.The results show that the longitudinal cracks on the blind hole step of 40Cr steel planetary carrier are quenching cracks.The reason is that the shape of the planetary carrier makes the cooling of the inner and outer martensite transformation non-isochronous,it leads more structure stress at the blind hole step of the planetary carrier,and when the local tangential tensile stress is greater than the fracture strength of martensite,resulting in quenching cracks.

关 键 词：行星架 纵向裂纹 淬火裂纹 不等时性 

分 类 号：TG142.1[一般工业技术—材料科学与工程]