应变速率对机车用钢锻件组织和性能的影响  

Effect of Strain Rates on Microstructure and Properties of Steel Forgings for Locomotive

作　　者：杜碧华[1] 

机构地区：[1]成都纺织高等专科学校,四川成都610041

出　　处：《热加工工艺》2016年第15期133-135,139,共4页Hot Working Technology

基　　金：四川省教育厅自然科学类重点项目(12ZA003)

摘　　要：采用Gleeble-3500热力模拟机分别用0.1、1、10 s^(-1)的应变速率对ZG25MnCrNiMo钢进行了热压缩变形试验,研究了应变速率对试样显微组织和硬度的影响。结果表明,当变形温度低于Ac_1时,试样组织为铁素体+珠光体,应变速率对组织形态影响不大,随着应变速率的增加,显微硬度先升高后降低,但变化幅度很小;当变形温度在Ac_1~Ac_3时,试样组织为索氏体+少量板条马氏体和铁素体,随着应变速率增加,板条马氏体的含量逐渐增加,铁素体含量逐渐减少,显微硬度逐渐升高;当变形温度高于Ac_3时,试样的显微组织为板条马氏体,随着应变速率增加,马氏体组织逐渐粗化,显微硬度降低。Hot compression deformation test at strain rates of 0.1, 1, 10 s-t for ZG25MnCrNiMo steel was carried out by using Gleeble-3500 thermo-mechanical simulator. The effects of strain rates on the microstructure and micro-hardness of samples were studied. The results show that, when the deformation temperature is lower than Ac1,the microstructure of the sample is ferrite ＋ pearlite.Strain rate has little effect on the microstructure.With the increase of stain tates, the micro-hardness increases firstly and then decreases, but the change range is very small. When the deformation temperature is between A c1 and Ac3, the microstructure of the sample is sorbite ＋ a small amount of lath martensite and ferrite. With the increase of strain rates, the content of lath martensite increases gradually, the ferrite content decreases, and hardness increases gradually. When the deformation temperature is higher than Ac3, the microstructure of the sample is lath martensite. With the increase of strain rates, the martensite gradually coarsenes, and the micro-hardness gradually decreases.

关 键 词：热模拟 应变速率 ZG25Mn CR NI MO 钢 组织和性能 

分 类 号：TG302[金属学及工艺—金属压力加工]