热轧变形量对铝热法制备的 2507双相不锈钢组织和力学性能的影响

对铝热反应制备的微纳结构2507双相不锈钢在1 000 ℃下进行了变形量为40%、60%和80%的轧制处理.利用X射线衍射仪(XRD)、光学显微镜(OM)、扫描电镜(SEM)、透射电镜(TEM)研究其轧制态显微组织.采用万能拉伸试验机和布洛维光学硬度计测试其力学性能.测试结果表明:轧制过程中,奥氏体和铁素体沿轧制方向被拉长,且奥氏体向铁素体转变.随着轧制变形量的增加,纳米晶平均晶粒尺寸变化不大,但体积分数减小.1 000 ℃下轧制变形量为40%、60%和80%后的屈服强度分别为232、284、456 MPa,抗拉强度分别为533、577、582 MPa,硬度分别为325、330、337 HV,延伸率分别为12.5%、11.1%和11.5%.

Effect of hot rolling deformation on microstructure and mechanical properties of 2507 duplex stainless steel prepared via the aluminothermic reaction

The 2507 duplex stainless steel with nano/micro-crystalline structure prepared by the aluminothermic reaction was subjected to a rolling treatment at 1 000 ℃ with 40%, 60% and 80% deformation. The microstructure of the as-rolled state was investigated by X-ray diffraction (XRD), optical microscopy (OM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The mechanical properties were measured by using a universal tensile testing machine and a Brook field optical hardness measuring instrument respectively. All measured results show that the rolling process makes austenite and ferrite phases elongated along the rolling direction and the transformation of austenite to ferrite happens in the steel as a result. With increase of rolling deformation, the nanocrystalline size does not change too much, while volume fraction of the nanocrystalline decreases. The yield strength of the steel is about 232, 284, 456 MPa, tensile strength is about 533, 577, 582 MPa, hardness is 325, 330, 337 HV, elongation takes 12.5%, 11.1% and 11.5% when the steel was rolled at 1 000 ℃ with 40%, 60% and 80% deformation, respectively.