Effects of PWHT on the impact toughness and fracture toughness of the weld metal under restraint welding

WANG Dongpo; LIU Kaiyue; DENG Caiyan; GONG Baoming; WU Shipin; XIAO Na

doi:10.12073/j.hjxb.20190914001

TRANSACTIONS OF THE CHINA WELDING INSTITUTION > 2020 > 41(8): 63-67, 78. > DOI: 10.12073/j.hjxb.20190914001

WANG Dongpo, LIU Kaiyue, DENG Caiyan, GONG Baoming, WU Shipin, XIAO Na. Effects of PWHT on the impact toughness and fracture toughness of the weld metal under restraint welding[J]. TRANSACTIONS OF THE CHINA WELDING INSTITUTION, 2020, 41(8): 63-67, 78. DOI: 10.12073/j.hjxb.20190914001

Citation:

PDF (974 KB)

Effects of PWHT on the impact toughness and fracture toughness of the weld metal under restraint welding

1.
Tianjin University, Tianjin, 300072, China
2.
Tianjin University of Technology and Education, Tianjin, 300222, China

More Information

Received Date: September 13, 2019
Available Online: July 12, 2020

Graphical Abstract

Abstract

Abstract

The post-weld heat treatment (PWHT) was conducted on the thick-plate DH36 weld metal under restraint welding, and the impact toughness and fracture toughness of the weld metal before and after PWHT were tested. The differences between the effects of PWHT on the impact toughness and fracture toughness were compared and analyzed, and its toughening mechanisms were investigated. The results show that the weld metal has well impact toughness on as-welded (AW) condition, but its fracture toughness is poor. After PWHT, there is no obvious change in the impact toughness of weld metal, but the fracture toughness increases significantly, with the average CTOD value rising from 0.123 mm to 0.707 mm. PWHT causes the improvement of toughness through the decrease of dislocation density, the significant reduction of dislocation tangles, and the precipitation and spheroidization of fine carbides. It can meanwhile eliminate the local embrittlement inside of the weld metal caused by the strain aging effects, thus improving the toughness. In addition, the results of the tested impact toughness of weld metal are quite different from those of the fracture toughness. Therefore, there may be risks in using single-temperature impact toughness as the only criterion to evaluate the toughness and the safety of the thick-plate weld metal under restraint welding.
- impact toughness,
- fracture toughness,
- post-weld heat treatment,
- restraint weld

FullText(HTML)

References (16)

References

吴世品. 海洋结构用钢DH36厚板焊接接头断裂韧性的研究[D]. 天津: 天津大学, 2012.

Wu Shipin. Study on the fracture toughness of welded joints of DH36 steel thick plate used in marine structures[D]. Tianjin: Tianjin University, 2012.

Zhang C, Yang S, Gong B, et al. Effects of post weld heat treatment (PWHT) on mechanical properties of C-Mn weld metal: Experimental observation and microstructure-based simulation[J]. Materials Science & Engineering A, 2017, 712: 430 − 439.

Yan C, Chen J H. Microstructure and toughness of local brittle zone of HSLA steel multipass weld metals[J]. China Welding, 1992, 1: 122 − 127.

温志刚, 靳伟亮, 张剑利, 等. 焊后热处理对DH36钢焊接接头断裂韧性的影响[J]. 焊接学报, 2013, 34(3): 89 − 93.

Wen Zhigang, Jin Weiliang, Zhang Jianli, et al. Influence of post weld heat treatment on fracture toughness of DH36 steel welded joints[J]. Transactions of the China Welding Institution, 2013, 34(3): 89 − 93.

Pacyna J, Witek L. The effect of carbides on fracture toughness of steels of ferritic matrix[J]. Steel Research, 1988, 59: 68 − 74. doi: 10.1002/srin.198801608

Lee S, Kim S, Hwang B, et al. Effect of carbide distribution on the fracture toughness in the transition temperature region of an SA 508 steel[J]. Acta Materialia, 2002, 50(19): 4755 − 4762. doi: 10.1016/S1359-6454(02)00313-0

Cheng G, Zhang F, Ruimi A, et al. Quantifying the effects of tempering on individual phase properties of DP980 steel with nanoindentation[J]. Materials Science & Engineering A, 2016, 667: 240 − 249.

Kuang C F, Li J, Zhang S G, et al. Effects of quenching and tempering on the microstructure and bake hardening behavior of ferrite and dual phase steels[J]. Materials Science and Engineering: A, 2014, 613: 178 − 183. doi: 10.1016/j.msea.2014.06.100

彭涛, 程时遐, 吉玲康, 等. X100管线钢在应变时效中的脆化[J]. 热加工工艺, 2013, 42(20): 179 − 181.

Peng Tao, Cheng Shixia, Ji Lingkang, et al. Embrittlement of X100 pipeline steel during strain aging[J]. Hot Working Technology, 2013, 42(20): 179 − 181.

Wen X, Wan M P, Huang C W, et al. Effect of microstructure on tensile properties, impact toughness and fracture toughness of TC21 alloy[J]. Material & Design, 2019, 180: 1 − 14.

许昌淦, 余刚. 冲击韧性与断裂韧性间关系的探讨[J]. 航空学报, 1990, 11(4): 182 − 187. doi: 10.3321/j.issn:1000-6893.1990.04.011

Xu Changgan, Yu Gang. A discussion on the relationship between impact toughness and fracture toughness[J]. Acta Aeronautica Et Astronautica Sinica, 1990, 11(4): 182 − 187. doi: 10.3321/j.issn:1000-6893.1990.04.011

BS 7448 Part l and Part 2. Fracture mechanics toughness tests, part 1. Method for determination of KIC, critical CTOD and critical J values of welds in metallic materials[S]. British Standards Institution,1997.

邓彩艳, 宋蒙蒙, 龚宝明, 等. 试样厚度对韧脆转变温度区间的影响[J]. 焊接学报, 2018, 39(5) : 1 − 4.

Deng Caiyan, Song Mengmeng, Gong Baoming, et al. Effect of specimen thickness on the shift of the ductile-to-brittle transition curve[J]. Transactions of the China Welding Institution, 2018, 39(5) : 1 - 4.

吴世品, 王东坡, 邓彩艳, 等. 焊缝CTOD试验中的Pop-in效应及产生原因[J]. 焊接学报, 2012, 33(4): 105 − 108.

Wu Shipin, Wang Dongpo, Deng Caiyan, et al. Investigation on Pop-in phenomenon and its causes in CTOD test for weld metal[J]. Transactions of the China Welding Institution, 2012, 33(4): 105 − 108.

Shi L, Yan Z, Liu Y, et al. Improved toughness and ductility in ferrite/acicular ferrite dual-phase steel through intercritical heat treatment[J]. Materials Science and Engineering: A, 2014, 590: 7 − 15. doi: 10.1016/j.msea.2013.10.006

Saha D C, Biro E, Gerlich A P, et al. Effects of tempering mode on the structural changes of martensite[J]. Materials Science and Engineering: A, 2016, 673: 467 − 475. doi: 10.1016/j.msea.2016.07.092

[1]	REN Wei, SHUAI Jian. The effect of welding method on the fracture toughness of X90 pipeline girth weld joints[J]. TRANSACTIONS OF THE CHINA WELDING INSTITUTION, 2024, 45(3): 32-42. DOI: 10.12073/j.hjxb.20230406001
[2]	WANG Dongpo, ZHANG Zixuan, GAO Wenbin, DENG Caiyan, LIANG Hang, WANG Ting. Comparative analysis of fracture toughness of EBW and TIG welded joints of TC4 titanium alloy[J]. TRANSACTIONS OF THE CHINA WELDING INSTITUTION, 2023, 44(8): 7-13. DOI: 10.12073/j.hjxb.20220921002
[3]	HUANG Yong, GUO Wei, WANG Yanlei. Effects of introductions of oxygen and nitrogen elements on impact toughness of gas pool coupled activating TIG weld metal[J]. TRANSACTIONS OF THE CHINA WELDING INSTITUTION, 2022, 43(5): 83-89. DOI: 10.12073/j.hjxb.20210919001
[4]	LIU Chang, DENG Caiyan, WANG Sheng, GONG Baoming. Critical fracture toughness of weld metal structure in submerged arc welding of EH36 steel[J]. TRANSACTIONS OF THE CHINA WELDING INSTITUTION, 2019, 40(3): 107-110. DOI: 10.12073/j.hjxb.2019400081
[5]	PEI Chong, WANG Dongpo, DENG Caiyan, GONG Baoming. Low temperature fracture toughness of welding metal of offshore platform steel in different welding positions[J]. TRANSACTIONS OF THE CHINA WELDING INSTITUTION, 2016, 37(3): 111-114,119.
[6]	DENG Caiyan, LEI Zhenyu, GONG Baoming, WANG Dongpo. Effect of post weld heat treatment on integrity of complex structure[J]. TRANSACTIONS OF THE CHINA WELDING INSTITUTION, 2015, 36(9): 5-8,34.
[7]	WEN Zhigang, JIN Weiliang, ZHANG Jianli, DENG Caiyan. Influence of post weld heat treatment on fracture toughness of DH36 steel welded joints[J]. TRANSACTIONS OF THE CHINA WELDING INSTITUTION, 2013, (3): 89-92.
[8]	HU Jie, JIANG Zhizhong, HUANG Jihua, CHEN Shuhai, ZHAO Xingke, ZHANG Hua. Effects of heat treatment processes on microstructure and impact toughness of weld metal of vacuum electron beam welding on CLAM steel[J]. TRANSACTIONS OF THE CHINA WELDING INSTITUTION, 2012, (11): 67-71.
[9]	MA Caixia, ZHANG Se, HUANG Xusheng, LIN Chengxiao, MA Fubao, YANG Siqian. Fracture toughness of square drill pipe joint by narrow gap welding[J]. TRANSACTIONS OF THE CHINA WELDING INSTITUTION, 2012, (4): 77-80.
[10]	Zhou Zhiliang, Liu Shuhua. Effect of PWHT on Fracture Toughness of HAZ in a DQTHT80 Steel[J]. TRANSACTIONS OF THE CHINA WELDING INSTITUTION, 1998, (1): 39-43.

Cited By

Cited by

Periodical cited type(2)

1.	周春东，章晓勇，彭勇，王克鸿，王剑春，周明. CMT Cycle Step工艺参数对焊缝表面特征纹路及成形尺寸的影响. 焊接学报. 2023(05): 95-101+134-135 . 本站查看
2.	韩蛟，韩永全，洪海涛，孙振邦. 基于光谱诊断的VPPA-MIG复合电弧耦合机理分析. 焊接学报. 2023(11): 104-109+134-135 . 本站查看

Other cited types(3)

Get Citation

PDF

XML

Article views (551) PDF downloads (60) Cited by(5)

Turn off MathJax

Article Contents

Abstract

References

Effects of PWHT on the impact toughness and fracture toughness of the weld metal under restraint welding