新型高氮高锰低镍奥氏体不锈钢模拟焊接热影响区组织和性能
发布时间：2019-01-05 08:55
【摘要】：焊接是奥氏体不锈钢板及型材的重要加工手段。高氮奥氏体不锈钢是用氮部分或完全取代镍以获得单相奥氏体组织的一类钢,可节约大量镍,降低成本,且具有优良的力学性能和耐腐蚀性能,因此获得了广泛的应用。但研究表明,高氮奥氏体不锈钢在焊接过程中可能会出现氮的损失、氮化物析出等问题,对接头的力学性能有不利影响。因此,对高氮奥氏体不锈钢焊接性能的研究具有实际意义。本论文使用Gleeble-3500型热/力模拟试验机对固溶处理后的一种新型高氮高锰低镍奥氏体不锈钢分别进行了峰值温度为1050℃~1300℃、线能量为5~12kJ/cm条件下的焊接热影响区(HAZ)模拟实验,并根据热模拟实验结果进行实际焊接;采用金相显微镜对模拟HAZ显微组织和焊接接头进行了分析,结合使用X射线.衍射、扫描电镜和透射电镜对模拟焊接HAZ显微组织进一步分析,并对热模拟实验钢和焊接接头进行拉伸、冲击和硬度测试,研究实验钢模拟焊接HAZ和实际焊接接头的力学性能。研究结果表明:不同峰值温度的热模拟实验后,实验钢晶粒随峰值温度的升高逐渐变大;抗拉强度、硬度随峰值温度升高逐渐降低,但均分别高于母材799MPa的抗拉强度及其硬度239.26HV;塑性略微低于母材,峰值温度对其影响不大;但在峰值温度为1150℃处呈现不一样的变化规律。实验钢在经历不同线能量的焊接热循环后,焊接HAZ组织主要为奥氏体和孪晶,晶粒中有(Cr,Mn,Fe)23C6析出,随着线能量的增加,此碳化物析出逐渐消失,晶粒也发生不同程度的长大;实验钢的塑性略低于母材,但线能量的变化对其塑性影响不大;实验钢硬度均高于母材,不存在软化区域;线能量为10kJ/cm时,实验钢具有最佳的力学性能,抗拉强度达到826MPa,延伸率54.6%,吸收功306.1J,硬度为319.03HV。采用优化后的试验参数对实验钢进行了TIG焊,焊接接头热影响区组织均匀,硬度高于母材,拉伸断口出现在焊缝上。
[Abstract]:Welding is an important means of processing austenitic stainless steel plates and profiles. High nitrogen austenitic stainless steel is a kind of steel which uses nitrogen partly or completely to replace nickel to obtain single-phase austenitic structure. It can save a lot of nickel, reduce cost, and has excellent mechanical properties and corrosion resistance, so it has been widely used. However, the study shows that the loss of nitrogen and the precipitation of nitride may occur in the welding process of high nitrogen austenitic stainless steel, which has a negative effect on the mechanical properties of the joints. Therefore, it is of practical significance to study the welding properties of high nitrogen austenitic stainless steel. In this paper, a new type of high nitrogen, high manganese and low nickel austenitic stainless steel after solid solution treatment was studied by using Gleeble-3500 thermal / mechanical simulator. The peak temperature of the austenitic stainless steel was 1050 鈩，
本文编号：2401548
[Abstract]:Welding is an important means of processing austenitic stainless steel plates and profiles. High nitrogen austenitic stainless steel is a kind of steel which uses nitrogen partly or completely to replace nickel to obtain single-phase austenitic structure. It can save a lot of nickel, reduce cost, and has excellent mechanical properties and corrosion resistance, so it has been widely used. However, the study shows that the loss of nitrogen and the precipitation of nitride may occur in the welding process of high nitrogen austenitic stainless steel, which has a negative effect on the mechanical properties of the joints. Therefore, it is of practical significance to study the welding properties of high nitrogen austenitic stainless steel. In this paper, a new type of high nitrogen, high manganese and low nickel austenitic stainless steel after solid solution treatment was studied by using Gleeble-3500 thermal / mechanical simulator. The peak temperature of the austenitic stainless steel was 1050 鈩，
本文编号：2401548
本文链接：https://www.wllwen.com/shoufeilunwen/boshibiyelunwen/2401548.html
