摘要
用三点弯曲疲劳试验测定了M2高速钢和含铌基体钢等三种工模具材料的疲劳裂纹扩展速率da/dN和门坎值ΔK_(th),并从合金成分和热处理工艺角度分析了显微组织的影响。试验结果表明:ΔK_(th)随基体韧性的改善,残余奥氏体的增加和晶粒尺寸的增大而提高;中速区da/dN主要取决于基体韧性的好坏,较多韧性相使其延缓,较大碳化物使其加速,而对晶粒尺寸不敏感。
The fatigue crack growth rate da/dN and threshold △K_(th) of 3 kinds of tool and die steelswere tested by means of 3-point bending specimens. The influence of their microstructure on△K_(th) and da/dN has been investigated in view of heat treatment and alloying elements, Theresults show that △K_(th) of steels investigated increases with the improvement of matrix tough-ness and the increases of retained austenite and grain size; the da/dN in the midrange dependson the toughness of matrix mainly, more toughness makes da/dN smaller, large size of undis-solved carbides accelerates da/dN, but da/dN is not sensitive to the grain size.
出处
《钢铁》
CAS
CSCD
北大核心
1989年第4期48-53,共6页
Iron and Steel
