钢带经逐级卷板加工、焊接而制成钢管，因前期加工硬化导致钢管硬度增大，从而会显著影响管件的二次成形加工.文中通过在304不锈钢管生产线搭建在线固溶处理试验平台，研究了固溶温度、固溶冷却条件及固溶保护气种类对304不锈钢管焊缝和母材微观组织及性能的影响.结果表明，在试验温度范围内，提高固溶温度会使热影响区和母材晶粒度增大，促进碳化物固溶于奥氏体晶粒，明显降低热影响区和母材的硬度.焊缝区沿奥氏体晶界分布的铁素体部分溶解，晶粒尺寸增大程度较小，因此焊缝区的硬度略有降低；而调整冷却条件对焊缝及母材的硬度影响不大；在氩气作为固溶保护气时，调节固溶参数，管件母材平均硬度可降低至188.7 HV，与未固溶时相比降低了11.0%.在氢气作为保护气时，平均硬度可降低至182.7 HV，与未固溶时相比降低了13.8%.通过显微组织观察，硬度、扩口和压扁力学性能测试，在两种保护气条件下固溶处理的管件均满足国家标准.
The steel strip is made into steel tube by rolling and welding step by step. The hardness of the steel tube increases due to the early work hardening, which will significantly affect the secondary forming processing of the tube. In this paper, the effects of solution temperatures, solution cooling conditions and types of solution shielding gas on the microstructure and properties of 304 stainless steel thin-walled tube were studied by building an on-line solution treatment test platform in the 304 stainless steel tube production line. The results show that increasing the solution treatment temperature in the experimental temperature range will increase the grain size of the heat-affected zone and the base metal and promote the solid solution of carbides in and along the austenite grains, so as to significantly reduce the hardness of the heat-affected zone and the base metal. The ferrite distributed along the austenite grain boundary in the weld zone is partially dissolved, and the grain size increases to a small extent, so the hardness of the weld zone decreases slightly. However, adjusting the cooling conditions has little effect on the hardness of the weld and base metal. When argon is used as the solution treatment protective gas, the average hardness of the base metal of the tube can be reduced to 188.7 HV, which is 11.0% lower than that without solution treatment. When hydrogen is used as solution treatment protective gas, the average hardness can be reduced to 182.7 HV, which is 13.8% lower than that without solution treatment. Through microstructure observation, hardness test, flaring and flattening mechanical properties test, the solution-treated tubes under the two protective gas conditions all meet the national standards.
[1] 王元清, 袁焕鑫, 石永久, 等. 不锈钢结构的应用和研究现状[J]. 钢结构, 2010, 25(2): 1 - 12
Wang Yuanqing, Yuan Huanxin, Shi Yongjiu, et al. Application and research status of stainless steel structure[J]. Steel Construction, 2010, 25(2): 1 - 12
[2] 韩豫, 陈学东, 刘全坤, 等. 奥氏体不锈钢应变强化工艺及性能研究[J]. 机械工程学报, 2012, 48(2): 6
Han Yu, Chen Xuedong, Liu Quankun, et al. Study of strain strengthening process and properties of austenitic stainless steel[J]. Journal of Mechanical Engineering, 2012, 48(2): 6
[3] 秦国梁, 马宏, 耿培皓, 等. 45钢/304不锈钢连续驱动摩擦焊接工艺[J]. 焊接学报, 2015, 36(8): 1 - 4
Qin Guoliang, Ma Hong, Geng Peihao, et al. 45 steel/304 stainless steel continuous drive friction welding process[J]. Transactions of the China Welding Institution, 2015, 36(8): 1 - 4
[4] 王延来, 刘世程, 刘德义, 等. 304奥氏体不锈钢固溶渗氮的研究[J]. 金属热处理, 2005, 30(5): 8 - 11
Wang Yanlai, Liu Shicheng, Liu Deyi, et al. Study of solid solution nitriding of 304 austenitic stainless steel[J]. Heat Treatment of Metals, 2005, 30(5): 8 - 11
[5] Glage A, Weidner A, Biermann H. Cyclic deformation behaviour of three austenitic cast CrMnNi TRIP/TWIP steels with various ni content[J]. Steel Research International, 2011, 82(9): 1040 - 1047.
[6] 刘巍. SA213-T P304奥氏体不锈钢固溶处理技术及应用[J]. 机械管理开发, 2014(4): 47 - 48
Liu Wei. SA213-T P304 austenitic stainless steel solid solution treatment technology and applications[J]. Mechanical Management and Development, 2014(4): 47 - 48
[7] 周慧, 李锡栋. 固溶处理对304不锈钢显微组织及力学性能的影响[J]. 热加工工艺, 2018, 47(24): 234 - 235
Zhou Hui, Li Xidong. Effect of solid solution treatment on microstructure and mechanical properties of 304 stainless steel[J]. Hot Working Technology, 2018, 47(24): 234 - 235
[8] 史勤益, 颜余仁, 赵先锐, 等. 304奥氏体不锈钢的热处理工艺研究[J]. 科学技术与工程, 2011, 11(24): 5910 - 5913
Shi Qinyi, Yan Yuren, Zhao Xianrui, et al. Heat treatment process study of austenitic stainless steel[J]. Science Technology and Engineering, 2011, 11(24): 5910 - 5913
[9] 郭国林, 刘鹏, 杨莉, 等. 热处理对304不锈钢板激光焊接接头组织和力学性能的影响[J]. 热加工工艺, 2016, 45(21): 194 - 196
Guo Guolin, Liu Peng, Yang Li, et al. The effect of heat treatment on the organization and mechanical properties of laser welded joints of 304 stainless steel sheet[J]. Hot Working Technology, 2016, 45(21): 194 - 196
[10] 唐峰. 热处理工艺对管用304不锈钢组织与性能的影响[D]. 成都: 成都理工大学, 2016.
Tang Feng. The effect of heat treatment process on the organization and properties of 304 stainless steel for pipes[D]. Chengdu: Chengdu University of Technology, 2016.
[11] 熊剑. 304不锈钢K-TIG焊电弧特性及接头性能研究[D]. 南昌: 南昌航空大学, 2019.
Xiong Jian. Study of K-TIG welding arc characteristics and joint performance of 304 stainless steel[D]. Nanchang: Nanchang Hangkong University, 2019.
[12] Lippod J C, Savage W F. Solidification of austenitic stainless steel weldments: part 2 - the effect of alloy composition on ferrite morphology[J]. Welding Journal, 1980, 59(2): 48s - 58s.
[13] EI-Batahyg A M. Effect of laser welding parameters on fusion zone shape and solidification structure of austenitic stainless steels[J]. Materials Letters, 1997, 32(2-3): 155 - 163.
[14] Christensen R M, Lo K H. Solutions for effective shear properties in three phase sphere and cylinder models - ScienceDirect[J]. Journal of the Mechanics and Physics of Solids, 1979, 27(4): 315 - 330.
[15] 王国强. 中厚板304不锈钢等离子弧焊接接头组织和性能的研究[D]. 苏州: 苏州大学, 2019.
Wang Guoqiang. Study on the organization and properties of plasma arc welded joints of 304 stainless steel in medium thickness plate[D]. Suzhou: Soochow University, 2019.
[16] 孙伟, 王萍. 固溶处理对新型奥氏体不锈钢焊接接头性能的影响[J]. 电焊机, 2010(2): 128 - 131
Sun Wei, Wang Ping. Effect of solid solution treatment on the properties of new austenitic stainless steel welded joints[J]. Electric Welding Machine, 2010(2): 128 - 131
[17] Ma H, Qin G, Geng P, et al. Effect of post-weld heat treatment on friction welded joint of carbon steel to stainless steel[J]. Journal of Materials Processing Technology, 2016, 277: 24 - 33.
[18] 上海市热处理协会. 实用热处理手册[M]. 上海: 上海科学技术出版社, 2009.
Shanghai Heat Treatment Association. Practical heat treatment handbook[M]. Shanghai: Shanghai Science and Technology Press, 2009.
