摘要
对汽车用22MnB5钢与26MnB5钢进行CCT曲线、显微组织以及显微硬度测试等对比试验,分析两种材料在组织性能上的差异。结果表明,26MnB5钢相较于22MnB5钢,CCT曲线明显向右、向下移动,贝氏体的转变上限温度Bs点有较大差异,因为碳的增高明显推迟了贝氏体转变;且随着冷却速度的增加,碳含量增加对铁素体和珠光体转变的推迟作用加大。由于26MnB5钢的终轧温度、卷取温度均高于22MnB5钢,所以26MnB5钢的带状组织更加明显。因此,较低的终轧温度可以减轻带状组织,此外,低温卷取可以保证层流冷却的冷却速率。材料的硬度随冷却速度加快而增大,在冷速为100℃/s时,22MnB5钢硬度为496 HV0.1,含碳量略高的26MnB5钢硬度更高,为516 HV0.1。
The CCT curve,microstructure and microhardness test of 22MnB5 steel and 26MnB5 steel for automobiles were carried out,and the differences in microstructure and properties between the two materials were analyzed.The results show that the CCT curve of 26MnB5 steel moves to the right and down obviously compared with 22MnB5 steel,and the upper limit temperature of Bs point of bainite transformation is quite different,because the increase of carbon obviously delays the bainite transformation.And with the increase of cooling rate,the delaying effect of carbon content on ferrite and pearlite transformation increases.As the finishing rolling temperature and coiling temperature of 26MnB5 steel are higher than those of 22MnB5 steel,the banded structure of 26MnB5 steel is more obvious.Therefore,a lower finishing temperature can reduce the banded structure,in addition,low-temperature coiling can ensure the cooling rate of laminar cooling.The hardness of the material increases with the increase of the cooling rate.When the cooling rate is 100℃/s,the hardness of 22MnB5 steel is 496 HV0.1,while the hardness of 26MnB5 steel with slightly higher carbon content is higher,516 HV0.1.
作者
汪思敏
栾道成
王正云
王楠
陈杰
胡志华
Wang Simin;Luan Daocheng;Wang Zhengyun;Wang Nan;Chen Jie;Hu Zhihua(School of Materials Science and Engineering,Xihua University,Chengdu Sichuan 610039 ,China)
出处
《金属热处理》
CAS
CSCD
北大核心
2019年第6期38-42,共5页
Heat Treatment of Metals
基金
四川省科技支撑项目(2017GZ0122
2017GZ0073
2018GZ0053)
四川省科技创新苗子工程项目(2017122)
西华大学创新基金(Ycjj2018176
Ycjj2018070
Ycjj2018069)
