Mn对无碳化物贝氏体钢组织和性能的影响  

Influence of Mn on microstructure and mechanical properties of carbide-free bainitic steel

作　　者：龙晓燕[1] 张福成[1,2] 康杰 李英男[1] 

机构地区：[1]燕山大学亚稳材料制备技术与科学国家重点实验室,河北秦皇岛066004 [2]燕山大学国家冷轧板带装备及工艺工程技术研究中心,河北秦皇岛066004

出　　处：《金属热处理》2017年第11期29-35,共7页Heat Treatment of Metals

基　　金：国家自然科学基金(51471146);河北省研究生创新资助项目(2016SJBS004)

摘　　要：对不同Mn含量(0、1.8、2.3和3.2wt%)的无碳化物贝氏体钢进行(Ms+10)℃等温转变和(Ms+10)^(Ms-20)℃连续冷却转变热处理,利用金相、XRD、TEM和EBSD等技术研究了Mn含量对钢组织性能的影响。结果表明:无Mn钢在Ms温度附近转变所得组织为贝氏体铁素体、残留奥氏体和仿晶界型铁素体混合组织,含Mn钢在Ms温度附近转变所得组织为下贝氏体,由板条状的贝氏体铁素体和片状的残留奥氏体组成,随Mn含量的提高,组织中残留奥氏体体积分数变化较小,贝氏体组织强度提高,塑性降低。Mn含量为2.3%时,综合性能最佳。Carbide-free bainitic steels alloyed with different Mn content（ 0,1. 8,2. 3 and 3. 2 wt%） was isothermal transformation treated at（ Ms ＋ 10） ℃,and continuous cooling transformation treated at（ Ms ＋ 10）-（ Ms-20） ℃. Effects of Mn content on microstructure and properties of the steels were investigated by metallography,XRD,TEM and EBSD. The results show that the mixed microstructure obtained after transformation close to Ms temperature in Mn-free steel consists of bainite ferrite,retained austenite,and grain boundary allotriomorphic ferrite. The transformation of Mn containing steel near the Ms temperature results in lower bainite,consisting of lath bainite ferrite and flaky residual austenite. With the Mn content increasing,the change of volume fraction of retained austenite is smaller,bainite strength increases and plasticity decreases. The tested steel with 2. 3% Mn exhibits the highest comprehensive performance.

关 键 词：锰含量 无碳化物贝氏体钢 组织 力学性能 

分 类 号：TG142[一般工业技术—材料科学与工程]