新型犁尖用33MnCrB5钢渗碳过程的DEFORM数值模拟  

DEFORM Numerical Simulation of Carburizing Process of 33MnCrB5 Steel for New Plow Tip

作　　者：师平 胡诗诚 SHI Ping;HU Shicheng(School of Aviation Engineering,Jiangsu Aviation Technical College,Zhenjiang 212134,China)

机构地区：[1]江苏航空职业技术学院航空工程学院,江苏镇江212134

出　　处：《热加工工艺》2023年第12期65-69,共5页Hot Working Technology

基　　金：镇江市科技计划项目(GY2020001)。

摘　　要：为了预测和减小犁尖用33MnCrB5钢在渗碳淬火过程中产生的组织和性能缺陷,采用DEFORM软件对33MnCrB5钢渗碳淬火过程进行了模拟,研究了淬火温度场、淬火应力场及淬火相变过程对犁尖形变的影响规律。模拟结果表明,经渗碳-淬火-回火处理后的33MnCrB5钢的渗碳层最高碳含量约为0.97wt%,最大硬度值约为60 HRC,渗碳层深度约为2.3 mm。在淬火冷却过程中,与心部基材相比,犁尖边缘及螺纹孔附近的冷却速度显著增大,导致该部位优先发生马氏体相变而产生体积突变,具体表现为这两位置处产生了最大变形量约为0.3 mm的形变。此外,由于温度变化产生的热应力及马氏体相变产生的组织应力的综合影响,犁尖表层最终表现为拉应力状态,心部表现为压应力状态。本研究可望为解决农业机械用耐磨硼钢渗碳淬火过程的组织缺陷和变形开裂问题提供参考。In order to predict and reduce the microstructure and performance defects produced during carburizing quenching of 33MnCrB5 steel,DEFORM software was used to simulate the carburizing and quenching process of 33MnCrB5 steel.The effects of quenching temperature field,quenching stress field and quenching phase transformation process on the deformation of plow tip were studied.The simulation results show that the carburized 33MnCrB5 steel after carburizing-quenching-tempering treatment has a maximum carbon content of about 0.97wt% in the carburized layer and shows a maximum hardness value of 60 HRC with a carburized layer depth of about 2.3 mm.Compared to the core base material,the cooling rate near the plow tip edge and threaded hole increases significantly during quenching and cooling,resulting in a preferential martensitic phase transformation and volume abruptness in this area,and a maximum deformation of about 0.3 mm at these two locations is formed.In addition,the surface layer of the plow tip eventually shows a state of tensile stress and the core shows a state of compressive stress,which is mainly attributed to the combined effects of thermal stress generated by temperature changes and microstructure stress generated by martensitic phase transformation.This study is expected to provide a reference for solving the problems of microstructure defects and deformation cracking in the carburizing and quenching process of wear-resistant boron steel for agricultural machinery.

关 键 词：耐磨性 应力场 渗碳工艺 数值模拟 犁尖 

分 类 号：TG156.81[金属学及工艺—热处理]