不同降温速率下带焊缝304LN钢的热应力对比

doi:10.13251/j.issn.0254-6051.2020.05.018

摘要/Abstract

摘要： 为探究降温速率对304LN钢材作深冷处理时的热应力是否造成不良影响,采用带有焊缝接头的304LN钢试件标定母材区、焊缝区及热影响区,分别做2 ℃/min、5 ℃/min和直接液氮浸泡的降温处理,并用有限元相关理论验证测试结果的合理性。试验结果发现:随着温度降低,钢板上下表面各处感知温度不相同,且试件边缘温度较中心处温度低,但温差较小;在持续降温过程中,试件的热应力随着降温速率的增加而提高,热应力与温度曲线呈现出非线性关系。在降温速率为5 ℃/min时析出物更加均匀稳定。在一般深冷处理过程中运用前两种速率降温差异性较小,但在实际的力学性能测试和相关工艺中建议以5 ℃/min为准。

关键词: 304LN钢焊接件, 深冷处理, 有限元模拟, 显微组织

Abstract: In order to explore whether the cooling rate had adverse effects on the thermal stress of the 304LN steel when it was cryogenic treated, 304LN specimens with welded joints was used to calibrate the base metal zone, weld zone and heat affected zone, respectively with the cooling treatment of 2 ℃/min, 5 ℃/min and direct liquid nitrogen immersion, and the rationality of the test results was verified by the finite element theory. The results show that with the decrease of temperatures, the perceived temperature of the upper and lower surfaces of the steel plate is different, and the temperature at the edge of the specimen is lower than that in the center, but the temperature difference is small. In the process of continuous cooling, the temperature stress of the specimen increases with the increase of cooling rates. According to the thermal stress-temperature curves, it is found that they have a nonlinear relationship. The precipitates are more uniform and stable at cooling rate of 5 ℃/min. Therefore, it can be concluded that there is little difference between the first two kinds of rates of cooling in general cryogenic processing, while 5 ℃/min is recommended based on the results of the practical mechanical properties testing and related processes.

Key words: 304LN steel welded parts, cryogenic treatment, finite element modelling, microstructure

中图分类号:

TG162.8

李扬, 黄中华, 沈子豪. 不同降温速率下带焊缝304LN钢的热应力对比[J]. 金属热处理, 2020, 45(5): 97-102.

Li Yang, Huang Zhonghua, Shen Zihao. Thermal stress comparison of 304LN steel with weld joint at different cooling rates[J]. Heat Treatment of Metals, 2020, 45(5): 97-102.

参考文献

[1]Rima Dey, Soumitro Tarafder, Sivaprasad S. Influence of phase transformation due to temperature on cyclic plastic deformation in 304LN stainless steel[J]. International Journal of Fatigue, 2016, 90: 148-157.
[2]Yin F, Yang L, Wang M, et al. Study on ultra-low cycle fatigue behavior of austenitic stainless steel[J]. Thin-Walled Structures, 2019, 143: 106-205.
[3]柴万里, 贺庆强, 王凤序, 等. 沿海大气环境304不锈钢法兰连接双头螺柱腐蚀开裂失效分析[J]. 金属热处理, 2019, 44(11): 223-226.
Chai Wanli, He Qingqiang, Wang Fengxu, et al. Failure analysis of corrosion and cracking of 304 stainless steel flange connection double- headed stud in coastal atmosphere[J]. Heat Treatment of Metals, 2019, 44(11): 223-226.
[4]Sivaprasad S, Surajit Kumar Paul, Arpan Das, et al. Cyclic plastic behaviour of primary heat transport piping materials: Influence of loading schemes on hysteresis loop[J]. Materials Science and Engineering: A, 2010, 527(26): 6858-6869.
[5]Juho Talonen, Hannu Hänninen, Pertti Nenonen, et al. Effect of strain rate on the strain-induced γ→α′-martensite transformation and mechanical properties of austenitic stainless steels[J]. Metallurgical and Materials Transactions A, 2005, 36(2): 421-432.
[6]Ashok Kumar, Singhal Lokesh. Effect of strain rate on martensitic transformation during uniaxial testing of AISI-304 stainless steel[J]. Metallurgical Transactions A, 1989, 20(12): 2857-2859.
[7]Dilip Maruthi G, Purushotham N, Rashmi R. Low temperature embrittlement studies on stainless steel 304 LN TIG welds[J]. Materials Today: Proceedings, 2018, 5(1): 2891-2900.
[8]高伟. 304LN不锈钢管材热挤压工艺参数研究[D]. 秦皇岛: 燕山大学, 2011.
Gao Wei. Research on hot extrusion processing properties for 304LN stainless steel pipe[D]. Qinhuangdao: Yanshan University, 2011.
[9]Swati Ghosh, Kain Vivekanand, Ray Ayan, et al. Deterioration in fracture toughness of 304LN austenitic stainless steel due to sensitization[J]. Metallurgical and Materials Transactions A, 2009, 40(12): 2938.
[10]Xin Jijun, Fang Chao, Huang Chuanjun, et al. Correlation between microstructure evolution and cryogenic fracture toughness in aging ITER-grade 316LN weldments[J]. Cryogenics, 2018, 96: 144-150.
[11]何德孚, 曹志樑, 蔡新强, 等. 含氮奥氏体不锈钢在焊管领域中的应用前景[J]. 钢管, 2006(5): 1-8.
He Defu, Cao Zhiliang, Cai Xinqiang, et al. Application prospect of nitrogen-containing austenitic stainless steel in welded pipe manufacturing industry[J]. Steel Pipe, 2006(5): 1-8.
[12]沈子豪, 李扬, 刘奎周. 深冷处理对304LN不锈钢板焊接接头组织和力学性能的影响[J]. 金属热处理, 2019, 44(8): 181-184.
Shen Zihao, Li Yang, Liu Kuizhou. Effect of deep cryogenic treatment on microstructure and mechanical properties of 304LN stainless steel plate welded joints[J]. Heat Treatment of Metals, 2019, 44(8): 181-184.
[13]Vishnuvardhan S, Gandhi P, Saravanan M, et al. Fracture studies on narrow gap welded SA 312 type 304LN stainless steel straight pipes under quasi-cyclic loading[J]. International Journal of Pressure Vessels and Piping, 2019, 174: 32-41.
[14]Li Yajing, Yu Dunji, Li Bingbing, et al. Martensitic transformation of an austenitic stainless steel under non-proportional cyclic loading[J]. International Journal of Fatigue, 2019, 124: 338-347.
[15]刘天佐, 魏玉忠, 马芹征, 等. Super304H钢650 ℃时效过程中析出相演化的定量分析[J]. 金属热处理, 2019, 44(12): 232-237.
Liu Tianzuo, Wei Yuzhong, Ma Qinzheng, et al. Quantitative analysis of evolution of precipitated phase in super 304H steel at 650 ℃[J]. Heat Treatment of Metals, 2019, 44(12): 232-237.
[16]Fan Shenggang, Jia Lianlian, Lyu Xiao, et al. Experimental investigation of austenitic stainless steel material at elevated temperatures[J]. Construction and Building Materials, 2017, 155: 267-285.
[17]Liu X, Zhao C, Zhao K. Microstructure evolution and mechanical/physical properties of 25# valve alloys steel subjected to deep cryogenic treatment[J]. Vacuum, 2019, 160: 394-401.
[18]Korade D N, Ramana K V, Jagtap K R, et al. Effect of deep cryogenic treatment on tribological behaviour of D2 tool steel-An experimental investigation[J]. Materials Today: Proceedings, 2017, 4(8): 7665-7673.
[19]Sun G F, Wang Z D, Lu Y, et al. Numerical and experimental investigation of thermal field and residual stress in laser-MIG hybrid welded NV E690 steel plates[J]. Journal of Manufacturing Processes, 2018, 34: 106-120.
[20]Hee Seon Bang, Han Sur Bang, You Chul Kim, et al. Analysis of residual stress on AH32 butt joint by hybrid CO₂ laser-GMA welding[J]. Computational Materials Science, 2010, 49(2): 217-221.
[21]Flores Johnson E A, Muránsky O, Hamelin C J, et al. Numerical analysis of the effect of weld-induced residual stress and plastic damage on the ballistic performance of welded steel plate[J]. Computational Materials Science, 2012, 58: 131-139.