高硅奥氏体不锈钢的热塑性  

Thermoplasticity of high silicon austenitic stainless steel

作　　者：胡勇[1,2] 王力华 欧阳明辉 胡永淇 褚成 HU Yong;WANG Lihua;OUYANG Minghui;HU Yongqi;CHU Cheng(State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals,Lanzhou University of Technology,Lanzhou 730050,Gansu,China;Wenzhou Pump and Valve Engineering Research Institute,Lanzhou University of Technology,Yongjia 325105,Zhejiang,China;Zhejiang Xuanda Group,Corrosion-resistant Special Metal Materials Research Institute,Yongjia 325105,Zhejiang,China)

机构地区：[1]兰州理工大学省部共建有色金属先进加工与再利用国家重点实验室,甘肃兰州730050 [2]兰州理工大学温州泵阀工程研究院,浙江永嘉325105 [3]浙江省宣达集团耐腐蚀特种金属材料研究院,浙江永嘉325105

出　　处：《钢铁研究学报》2024年第1期108-120,共13页Journal of Iron and Steel Research

基　　金：浙江省基础公益研究计划资助项目(LGG21E010008);兰州理工大学红柳一流学科建设基金资助项目(CGZH001);甘肃省教育厅“双一流”科研重点资助项目(GSSYLXM-03)。

摘　　要：采用Gleeble-3500热模拟机对不同凝固模式和组织特点的高硅奥氏体不锈钢进行高温拉伸和压缩实验,通过JMatPro软件计算、OM(光学显微镜)、SEM/EDS(扫描电镜/能谱分析)、EPMA(电子探针)等方法研究了高硅奥氏体不锈钢的热塑性变化规律。结果表明:以FA模式(以铁素体为最先析出相)凝固的6.0%(质量分数,余同)Si铸态试样由于析出相及类魏氏体组织的存在热塑性最差;经过1150℃×12h均匀化处理后,6.0%Si试样形成单一奥氏体组织,具有76%的断面收缩率和13%的伸长率,拉伸断口呈现韧性断裂特征,热塑性得到显著改善;当6.0%Si试样经过1200℃×12h均匀化处理后,大量高温δ铁素体会重新析出,热塑性显著下降,断口呈现沿晶断裂特征;结合热压缩实验表明,6.0%Si试样中适量椭圆形高温δ铁素体的存在有利于DRX(动态再结晶)的发生。High temperature tensile and compression experiments on high silicon austenitic stainless steel with different solidification modes and microstructure characteristics were adopted using the Gleeble-3500 thermal simulation machine.The JMatPro software,OM(optical microscope),SEM/EDS(scanning electron microscope/energy dispersive spectrometer)and EPMA(electron probe),were used to studied the thermoplastic variation of high silicon austenitic stainless steel.The results show that the as-cast 6.0 wt.%Si samples solidified in FA mode(with ferrite as the first precipitated phase)have the worst thermo-plasticity,due to the existence of precipitated phase and Weistier-like structure.After homogenization at 1150℃×12h,the solo austenitic structure of 6.0 wt.%Si samples was formed with the section shrinkage reached 76%and elongation 13%.The tensile fracture shows the ductile fracture characteristics and the thermo-plasticity were significantly improved.After the 6.0 wt.%Si sample was homogenized at 1200℃×12h,a large amount of high temperatureδferrite precipitates again,and the thermo-plasticity decreases significantly as well the fracture took on the characteristics of inter-granular fracture.Combined with hot compression experiments,DRX(dynamic recrystallization)is favored when a moderate amount of elliptical high-temperatureδferrite is present in the 6.0 wt.%Si specimen.

关 键 词：高硅奥氏体不锈钢 Δ铁素体 均匀化处理 热塑性 二次析出 

分 类 号：TG142.71[一般工业技术—材料科学与工程]