基于汽车转向活塞锻造遗留效应的预先热处理工艺优化  

Preheat treatment process optimization based on forging legacy effect for automobile steering piston

作　　者：毛胜辉[1] 付甲 Mao Shenghui;Fu Jia(School of Mechatronics Engineering,Zhengzhou Railway Vocational and Technical College,Zhengzhou 451460,China;School of Materials Science and Engineering,Xifan Shiyou University,Xi’an 710065,China)

机构地区：[1]郑州铁路职业技术学院机电工程学院,河南郑州451460 [2]西安石油大学材料科学与工程学院,陕西西安710065

出　　处：《锻压技术》2020年第7期182-186,共5页Forging & Stamping Technology

基　　金：国家自然科学基金资助项目(51905427)。

摘　　要：针对某型号汽车转向活塞交付过程中多次出现组织粗大、混晶的现象,采用理论分析和实验研究相结合的方法,对其锻造和预先热处理工艺过程进行了分析和研究。根据转向活塞成形过程的工艺特点,结合塑性成形过程中变形量和变形温度与再结晶之间的关系,分析了不同变形部位的再结晶状态,从原理上指出了现有锻造余热正火工艺的不足。根据奥氏体的形核、长大、均匀化机制,结合过冷奥氏体分解所需要的条件,设计了转向活塞加热、风冷、等温的3步走的预先热处理工艺方案。优化了转向活塞的预先热处理工艺,消除了因锻造带来的遗留效应,为后期的机械加工和渗碳淬火奠定了技术基础。For the phenomenon that the coarse microstructure and mixed crystal frequently occur in the delivery for a certain type of automobile steering piston,the forging and preheat treatment processes were analyzed and studied by combining theoretical analysis and experimental research.According to the technological characteristics of steering piston forming process,combining with the relationships among deformation amount,deformation temperature and recrystallization,the recrystallization states in different deformation positions were analyzed,and the shortage of present forging waste heat normalizing process was pointed out in principle.Based on the mechanism of austenite nucleation,growth and homogenization,combining with the requirements of undercooled austenite decomposition,the threestep preheat treatment process scheme of steering piston including heating,air cooling and isothermal transformation was designed,and the preheat treatment process of steering piston was optimized to eliminate the legacy effect caused by forging,which provided technical guarantee for the practical mechanical processing and carburizing and quenching.

关 键 词：转向活塞 锻造遗留效应 预先热处理 混晶 再结晶 

分 类 号：TG311[金属学及工艺—金属压力加工]