Thermal stability of retained austenite and mechanical properties of medium-Mn steel during tempering treatment
Thermal stability of retained austenite and mechanical properties of medium-Mn steel during tempering treatment
复制标题
DOI：
10.1016/s1006-706x(17)30123-1
复制
发表时间：
2017-08
影响因子：
2.5
通讯作者：
Xiaoli Zhao;Yongjia Zhang;C. Shao;W. Hui;Han. Dong
中科院分区：
文献类型：
--
作者：
Xiaoli Zhao;Yongjia Zhang;C. Shao;W. Hui;Han. Dong
采用x射线衍射仪（XRD）、透射电镜（TEM）和拉伸试验研究了在200 ~ 500℃回火过程中，以铁素体和残余奥氏体为起始超细层状双相组织的0.1 C- 5mn钢的残余奥氏体（RA）热稳定性和经淬火和临界间退火后的力学性能。结果表明：当回火温度达到400℃时，RA体积分数随回火温度的升高而略有下降，导致极限抗拉强度（UTS）略有升高，总伸长率（TE）略有下降；因此，得到了高达31 GPa•%的UTS - to - TE (utsx - TE)，并且几乎保持不变。然而，在500℃回火时，一部分RA开始分解，导致RA分数下降~ 35%，utsxte值下降~ 16%。结果表明，在回火温度达到400℃时，超细层状双相组织具有较好的稳定性，并能保持良好的强度和塑性结合。因此，在温度不高于400℃的条件下，镀锌等热处理工艺是可行的。
The thermal stability of retained austenite (RA) and the mechanical properties of the quenched and intercritical annealed 0.1 C-5Mn steel with the starting ultrafine lamellar duplex structure of ferrite and retained austenite during tempering within the range from 200 to 500 C were studied by X-ray diffraction (XRD), transmission electron microscopy (TEM) and tensile testing. The results showed that there was a slight decrease in the RA volume fraction with increasing tempering temperature up to 400 C. This caused a slight increase in the ultimate tensile strength (UTS) and a slight decrease in the total elongation (TE); thus, the product of UTS to TE (UTS× TE) as high as 31 GPa•% was obtained and remained nearly unchanged. However, a portion of the RA began to decompose when tempered at 500 C and thus caused a~ 35% decrease of the RA fraction and a~ 16% decrease of the value of UTS× TE. It is concluded that the ultrafine lamellar duplex structure is rather stable and the excellent combination of strength and ductility could be retained with tempering temperature up to 400 C. Thus, thermal processes such as galvanization are feasible for the tested steel provided that their temperatures are not higher than 400 C.