Mn18Cr18N高氮奥氏体不锈钢的高温力学性能  

High temperature mechanical properties of Mn18Cr18N high nitrogen austenitic stainless steel

作　　者：王英虎 郑淮北 白青青 宋令玺 胡进[2] 黄博 Wang Yinghu;Zheng Huaibei;Bai Qingqing;Song Lingxi;Hu Jin;Huang Bo(Chengdu Advanced Metal Material Industry Technology Research Institute Co.,Ltd.,Chengdu Sichuan 610000,China;Pangang Group Jiangyou Changcheng Special Steel Co.,Ltd.,Jiangyou Sichuan 621704,China)

机构地区：[1]成都先进金属材料产业技术研究院股份有限公司,四川成都610000 [2]攀钢集团江油长城特殊钢有限公司,四川江油621704

出　　处：《金属热处理》2022年第1期172-177,共6页Heat Treatment of Metals

摘　　要：采用Gleeble-2000热模拟试验机对Mn18Cr18N高氮奥氏体不锈钢进行高温拉伸试验,利用扫描电镜-能谱仪对拉伸试样断口形貌及断口附近的显微组织进行观察,用Thermo-Calc软件计算试验钢的相变及析出相,研究了Mn18Cr18N高氮奥氏体不锈钢的高温力学性能。结果表明,试验钢的第Ⅰ脆性区>1200℃,第Ⅲ脆性区为850~950℃,未出现第Ⅱ脆性区,第Ⅰ脆性区的出现主要是在加热过程中试验钢由γ奥氏体向δ铁素体转变引起的,第Ⅲ脆性区的出现是因为沿晶析出M_(23)C_(6)、M_(2)(C, N)等硬脆相引起的;试验钢的抗拉强度随着拉伸温度升高而降低,断面收缩率在1000~1200℃温度范围内逐渐增大并表现出极佳的热塑性,断面收缩率均在70%以上,温度超过1200℃后断面收缩率急剧下降;Mn18Cr18N高氮奥氏体不锈钢的热锻温度应选择在1000~1150℃之间,在此温度范围内试验钢的断面收缩率均在70%以上,并且可以避开第Ⅰ与第Ⅲ脆性区。High temperature mechanical properties of the Mn18 Cr18 N high nitrogen austenitic stainless steel were studied, with the high temperature tensile test being carried out by Gleeble-2000 thermal simulation testing machine, the fracture morphology and vicinity microstructure of the tensile specimens being observed by scanning electron microscopy-energy dispersive spectrometer, and the phase transformation and precipitated phases of the tested steel being studied by Thermo-Calc calculation. The results show that the corresponding temperature of brittle zone Ⅰ of the tested steel is higher than 1200 ℃, and that of brittle zone Ⅲ is 850-950 ℃, while the brittle zone Ⅱ does not appear. The appearance of the brittle zone Ⅰ is mainly caused by the transformation from γ austenite to δ ferrite during heating process of the tested steel, and that of the brittle zone Ⅲ is caused by the intergranular hard and brittle precipitated phases such as M_(23)C_(6)and M_(2)(C, N). With the increase of tensile test temperature, the tensile strength of the tested steel decreases. The reduction of area gradually increases in the temperature range of 1000-1200 ℃ and shows excellent thermoplasticity, which is above 70%. While when the temperature exceeds 1200 ℃, the reduction of area decreases sharply. The hot forging temperature of the Mn18 Cr18 N high nitrogen austenitic stainless steel should be selected between 1000 ℃ and 1150 ℃, during which the reduction of area of the tested steel is above 70%, and the brittle zones Ⅰ and Ⅲ can be avoided.

关 键 词：高氮奥氏体不锈钢 高温力学性能 高温拉伸试验 强塑性 THERMO-CALC软件 

分 类 号：TG142.7[一般工业技术—材料科学与工程]