铸态42CrMo钢高温拉伸变形中工艺参数和动态再结晶对空洞演化的影响及微观损伤机理分析  

Influence of process parameters and dynamic recrystallization on void evolution and analysis on microscopic damage mechanism for as-cast 42CrMo steel in high temperature tensile deformation

作　　者：陈园园 齐会萍[2] 李永堂[2] 刘慧玲[1] Chen Yuanyuan;Qi Huiping;Li Yongtang;Liu Huiling(College of Mechanical Engineering,Jinzhong University,Jinzhong 030619,China;College of Materials Science and Engineering,Taiyuan University of Science and Technology,Taiyuan 030024,China)

机构地区：[1]晋中学院机械系,山西晋中030619 [2]太原科技大学材料科学与工程学院,山西太原030024

出　　处：《锻压技术》2023年第8期243-252,共10页Forging & Stamping Technology

基　　金：国家自然科学基金资助项目(51875383,51575371);山西省高校科技创新项目(2020L0579)。

摘　　要：用热模拟实验机对铸态42CrMo钢进行高温拉伸实验,分析了断口及断口附近的微观组织、空洞演化与温度、应变速率及应变之间的关系,探讨了工艺参数和动态再结晶行为对空洞演化的影响,研究了铸态42CrMo钢的微观损伤机理。结果表明:铸态42CrMo钢的变形温度控制在1423~1473 K,并控制应变速率和应变,可以抑制高温拉伸变形中的空洞萌生、长大和聚集;发生动态再结晶行为时,微空洞不易形核和长大,空洞之间聚集的间距减小,增加了断裂应变;铸态42CrMo钢高温拉伸变形过程中,氧化硅、硫化锰、氧化铝和氧化钙等夹杂物的脱落或破裂导致空洞形核,且马氏体晶粒之间也可形核。The high-temperature tensile experiments of as-cast 42CrMo steel were conducted by thermal simulation experimental machine,and the relationships between microstructures at the fracture and near the fracture,void evolution and temperature,strain rate and strain were analyzed.Then,the influences of process parameters and dynamic recrystallization behavior on void evolution were discussed,and the microscopic damage mechanism of as-cast 42CrMo steel was studied.The results show that the initiation,growth and aggregation of viods in the high-temperature tensile deformation can be inhibited by controlling the deformation temperature of as-cast 42CrMo steel at 1423-1473 K and controlling the strain rate and strain.When dynamic recrystallization behavior occurs,the micro-voids are not easy to nucleate and grow,the spacing of aggregation between voids is reduced,and the fracture strain is increased.In the process of high-temperature tensile deformation of as-cast 42CrMo steel,the fall off or break of inclusions such as silica oxide,manganese sulfide,aluminum oxide and calcium oxide leads to void nucleation,and the nucleation can also occur between martensite grains.

关 键 词：铸态42CrMo钢 动态再结晶 断口组织 空洞演化 夹杂物 

分 类 号：TG333[金属学及工艺—金属压力加工]