摘要
用端淬法研究了0.005wt%Ca 对42MnCr 钢淬透性及不同热处理状态下室温冲击韧性和显微组织的影响,用 Auger 能谱(AES)分析了沿晶断口表面 Ca 及其它元素的含量。结果表明,微 Ca 钢的淬透性稍高于无 Ca 钢;微 Ca 钢在所研究的热处理状态下的室温冲击韧性均明显高于无Ca 钢。Auger 能谱分析表明,Ca 在奥氏体晶界有明显的偏聚现象,并促进 C 的晶界偏聚,显著减小 S 的晶界偏聚。认为 Ca 的晶界偏聚及其对 S、C 晶界偏聚的互作用是影响钢的组织与冲击韧性的重要因素。
Effect of Ca on the hardenabilily,microstructures and impacttoughness at room temperature of normatizcd 42MnCr steel has been investiga-ted.An addition of 0.005wt% Ca to 42MnCr steel may improve markedly theimpacttoughness at room temperature,inhibits the intergranular fracture,andthe precipitation of pre-eutectoid ferrite at grain boundaries of austenite.AE S analysis showed that the Ca segregates obviously along austenite grainboundaries,and inhibits markedly the segregations of S.It is believed thatan important reason to improve toughncss may attributes to the segregations ofCa and the interactions with other elements in steels.
关键词
淬透性
冲击韧性
晶界偏聚
钢
钙
Ca microalloying
hardenability
impact toughness
glain boundary segregation
