焊后热处理温度对G115/T92异种钢接头组织及力学性能的影响
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摘要
利用钨极氩弧焊(GTAW)和手工电弧焊(SMAW),采用767、774、790℃3种焊后热处理温度对G115/T92异种钢进行焊接试验,并利用光学显微镜、显微硬度仪、拉伸试验机、冲击试验机等对焊接接头的显微组织及力学性能进行研究。结果表明:接头焊缝、热影响区均为典型的回火马氏体组织,T92钢侧熔合线附近δ-铁素体的体积分数分别为0. 3%、0. 1%、0. 1%。随着焊后热处理温度升高,显微硬度、室温强度降低,焊缝冲击吸收能量增大,室温强度和冲击吸收能量均符合母材标准要求。室温拉伸断裂均发生在T92钢侧母材,650℃高温断口位于T92钢侧不完全相变区。推荐焊后热处理温度为(770±5)℃,偏上限控制。
The experimental study on the welding process of G115/T92 dissimilar steels was conducted using gas tungsten arc welding( GTAW) and shielded metal arc welding( SMAW) with post-weld heat treatment( PWHT) temperature of 767 ℃,774 ℃ and 790 ℃,respectively,then the microstructure and mechanical properties of the welded joints were investigated by means of optical microscope,hardness,tensile and impact tests. The results show that the welding seam and heat-affected zone( HAZ) of the joints have a typical tempered martensite structure. The volume fraction of polygonal δ-ferrite near the fusion line is 0. 3%,0. 1% and 0. 1%,respectively. With the increase of PWHT temperature,Vickers hardness and strength at room temperature decrease while impact absorbed energy increases.Both of room temperature strength and impact absorbed energy meet the requirement of base metal standards. All the tensile fracture occurs in base metal of T92 steel at room temperature while in the ICHAZ of T92 steel side at 650 ℃. The PWHT temperature should be controlled in the range of( 770 ± 5) ℃,and the upper limit is recommended.
The experimental study on the welding process of G115/T92 dissimilar steels was conducted using gas tungsten arc welding( GTAW) and shielded metal arc welding( SMAW) with post-weld heat treatment( PWHT) temperature of 767 ℃,774 ℃ and 790 ℃,respectively,then the microstructure and mechanical properties of the welded joints were investigated by means of optical microscope,hardness,tensile and impact tests. The results show that the welding seam and heat-affected zone( HAZ) of the joints have a typical tempered martensite structure. The volume fraction of polygonal δ-ferrite near the fusion line is 0. 3%,0. 1% and 0. 1%,respectively. With the increase of PWHT temperature,Vickers hardness and strength at room temperature decrease while impact absorbed energy increases.Both of room temperature strength and impact absorbed energy meet the requirement of base metal standards. All the tensile fracture occurs in base metal of T92 steel at room temperature while in the ICHAZ of T92 steel side at 650 ℃. The PWHT temperature should be controlled in the range of( 770 ± 5) ℃,and the upper limit is recommended.
引文
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[13]胡小强,肖纳敏,罗兴宏,等.含W型10%Cr超超临界钢中δ-铁素体的微观结构及其对力学性能的影响[J].金属学报,2009,45(5):553-558.Hu Xiaoqiang,Xiao Namin,Luo Xinghong,et al. Effects ofδ-ferrite on the microstructure and mechanical properties in a tungsten-alloyed10%Cr ultra-supercritical steel[J]. Acta Metallurgica Sinica,2009,45(5):553-558.
[14]S'loderbach Z,Pajk J. Determination of ranges of components of heat affected zone including changes of structure[J]. Archives of Metallurgy and Materials,2015,60(4):2607-2612.
[2]Liu Z,Bao H,Chen Z. G115 steel and its application for 600+℃AUSC-PP[C]//8th International Conference on Advances in Materials Technology for Fossil Power Plants. Albufeira, Algarve, Portugal,2016:1011-1018.
[3]吴军,邹增大,王新洪,等.控轧控冷T92耐热钢的显微组织结构研究[J].金属热处理,2007,32(9):71-74.Wu Jun,Zou Zengda,Wang Xinhong,et al. Microstructure of T92heat resistant steel manufacturing by TCMP[J]. Heat Treatment of Metals,2007,32(9):71-74.
[4]Lundin C D. Dissimilar metal welds-transition joints literature review[J]. Welding Journal,1982,61(2):58-63.
[5]Cao J,Gong Y,Zhu K,et al. Microstructure and mechanical properties of dissimilar materials joints between T92 martensitic and S304H austenitic steels[J]. Materials&Design,2011,32(5):2763-2770.
[6]Cao J,Gong Y,Yang Z G. Microstructural analysis on creep properties of dissimilar materials joints between T92 martensitic and HR3C austenitic steels[J]. Materials Science and Engineering:A,2011,528(19/20):6103-6111.
[7]刘广慧,刘振兴.焊后热处理对T92/HR3C异种钢焊接接头组织与冲击性能的影响[J].金属热处理,2013,38(10):32-34.Liu Guanghui,Liu Zhenxing. Effects of postweld heat treatment on microstructure and impact property of T92/HR3C dissimilar steel welding joints[J]. Heat Treatment of Metals,2013,38(10):32-34.
[8]刘伟伟,孙华,郭俊飞. EPRI P87焊接T92与TP347H异种钢焊接工艺研究[J].焊接技术,2013,42(12):62-64.
[9]Kim M Y,Kwak S C,Choi I S,et al. High-temperature tensile and creep deformation of cross-weld specimens of weld joint between T92martensitic and Super304H austenitic steels[J]. Materials Characterization,2014,97:161-168.
[10]Zhang J,Huang B,Wu Q,et al. Effect of post-weld heat treatment on the mechanical properties of CLAM/316L dissimilar joint[J]. Fusion Engineering&Design,2015,100(5):334-339.
[11]Falat L, CˇiripováL, KepicˇJ, et al. Correlation between microstructure and creep performance of martensitic/austenitic transition weldment in dependence of its post-weld heat treatment[J].Engineering Failure Analysis,2014,40(2):141-152.
[12]李林平,梁军,赵雷,等. G115/T92异种钢焊接接头的显微组织及力学性能[J].材料热处理学报,2018,39(9):138-144.Li Linping, Liang Jun, Zhao Lei, et al. Microstructure and mechanical properties of G115/T92 dissimilar welded joints[J].Transactions of Materials and Heat Treatment, 2018, 39(9):138-144.
[13]胡小强,肖纳敏,罗兴宏,等.含W型10%Cr超超临界钢中δ-铁素体的微观结构及其对力学性能的影响[J].金属学报,2009,45(5):553-558.Hu Xiaoqiang,Xiao Namin,Luo Xinghong,et al. Effects ofδ-ferrite on the microstructure and mechanical properties in a tungsten-alloyed10%Cr ultra-supercritical steel[J]. Acta Metallurgica Sinica,2009,45(5):553-558.
[14]S'loderbach Z,Pajk J. Determination of ranges of components of heat affected zone including changes of structure[J]. Archives of Metallurgy and Materials,2015,60(4):2607-2612.