Fracture analysis of self sealing tension bolt of high pressure regulating valve

doi:10.13251/j.issn.0254-6051.2021.07.047

Abstract

Abstract: Fracture causes of two self sealing tension bolts of high pressure regulating valve were analyzed by means of macroscopic and microscopic observation, chemical composition analysis, mechanical property tests, and microstructure observation. The results show that the material of the two bolts is 1Cr11Co3W3NiMoVNbNB steel. The plasticity and toughness of one hurt bolt (No.91 in the text) can not meet the requirements. There is harmful Laves phase observed in the structure, which is prone to fracture by impact. There is an original crack at the root of second to third screw of the bolt ,and a pit like crack source at the root of the third to fourth screw of the another hurt bolt, which may initiate during service at high temperature. Both bolts are broken rapidly due to impact load while disassembled at room temperature.

Key words: 1Cr11Co3W3NiMoVNbNB steel, bolt, fracture, impact load

CLC Number:

TG142.41

Xie Zengxiao, Huang Yijun, Zhang Yufei, Lou Yumin, Pu Xianchao. Fracture analysis of self sealing tension bolt of high pressure regulating valve[J]. Heat Treatment of Metals, 2021, 46(7): 242-248.

References

[1] 朱小阳. 1Cr11Co3W3NiMoVNbNB钢的试制[J]. 特钢技术, 2010, 16(3): 18-23.
Zhu Xiaoyang. Trial production of 1Cr11Co3W3NiMoVNbNB steel[J]. Special Steel Technology, 2010, 16(3): 18-23.
[2] 赵成志, 魏双胜, 高亚龙, 等. 超临界与超超临界汽轮机耐热钢的研究进展[J]. 钢铁研究学报, 2007, 19(9): 1-5.
Zhao Chengzhi, Wei Shuangsheng, Gao Yalong, et al. Progress of heat-resistant steel for super critical and ultra-supercritical steam turbine[J]. Journal of Iron and Steel Research, 2007, 19(9): 1-5.
[3] 彭以超, 楼玉民, 徐绍平, 等. 超超临界机组中压汽门阀盖Alloy783合金螺栓断裂失效分析[J]. 热力发电, 2018, 47(3): 115-122.
Peng Yichao, Lou Yumin, Xu Shaoping, et al. Fracture failure analysis on Alloy783 bolts in medium-pressure valve bonnets of USC units[J]. Thermal Power Generation, 2018, 47(3): 115-122.
[4] 丁建生, 刘蔺勋. 热处理对超超临界材料KT5331AS0组织和性能的影响[J]. 热加工工艺, 2010, 39(8): 165-167.
Ding Jiansheng, Liu Linxun. Effects of heat treatment on microstructure and properties of ultra-supercritical KT5331 AS0 steel[J]. Hot Working Technology, 2010, 39(8): 165-167.
[5] 龚志华, 杨钢, 定巍, 等. 热处理工艺对叶片用KT5331钢组织和性能的影响[J]. 金属热处理, 2017, 42(10): 66-70.
Gong Zhihua, Yang Gang, Ding Wei, et al. Effect of heat treatment on microstructure and properties of KT5331 steel used for blade[J]. Heat Treatment of Metals, 2017, 42(10): 66-70.
[6] 何玉东. Laves相对10Cr11Co3W3NiMoVNbNB钢高温持久性能影响的探讨[J]. 特钢技术, 2018, 24(3): 9-14, 32.
He Yudong. Effect of laves phase on stress rupture properties of steel 10Cr11Co3W3NiMoVNbNB at high temperature[J]. Special Steel Technology, 2018, 24(3): 9-14, 32.
[7] 钟群鹏, 赵子华. 断口学[M]. 北京: 高等教育出版社, 2006: 190-197.

[1]	Chen Dongjun, Li Guangyang, Liu Gang. Effect of aging treatment on microstructure and mechanical properties of AlSi9Cu3 HPDC aluminum alloy [J]. Heat Treatment of Metals, 2022, 47(4): 53-56.
[2]	Li Mingxiang, Yang Ping, He Wei, Zhang Meng, Wang Wenbo. Failure analysis of hydrogen induced delayed fracture of 50CrVA steel spring [J]. Heat Treatment of Metals, 2022, 47(3): 257-260.
[3]	Yang Yuchuan, Li Wei, Xiong Yong. Analysis of fracture cause of 1Cr17Ni2 steel small shaft of control box [J]. Heat Treatment of Metals, 2022, 47(3): 261-265.
[4]	Li Dejun, Gao Hua, Kong Xianglu, Yang Xiaoping, Li Ta, Dong Zhaoyuan, Zhang Xiaojia. Failure analysis of 20 steel equal-diameter tee [J]. Heat Treatment of Metals, 2022, 47(2): 262-266.
[5]	Zhao Xiaojun, Liang Xiao, Cai Zhenyang, Xiao Lairong. Effect of aluminizing and oxidation treatment on microstructure and mechanical properties of CLAM steel [J]. Heat Treatment of Metals, 2022, 47(1): 192-196.
[6]	Wu Hao, Deng Xiangtao, Li Chengru, Sui Yi, Zhang Tao, Ji Wenbo, Wang Zhaodong. Analysis on cold bending fracture of wear-resistant steel NM400 [J]. Heat Treatment of Metals, 2021, 46(9): 262-267.
[7]	Xu Qihao,Yang Lilin, Xia Ming, Qin Chen, Geng Zhenyue, Jiang Yajun, Zhao Liping. Failure analysis of 38CrMoAlA steel driveshaft [J]. Heat Treatment of Metals, 2021, 46(9): 268-272.
[8]	Nie Xiaolong, Gao Jiaqiang, Meng Kairen, Wang Junyi, Liu Xinkuan. Fracture failure analysis of 60Si2Mn spring steel [J]. Heat Treatment of Metals, 2021, 46(8): 246-249.
[9]	Song Quan, Dan Ting, Li Xiaoguang, Gao Mingsen, Cao Huihui. Fracture cause analysis of W6Mo5Cr4V2Al high speed steel twist drill [J]. Heat Treatment of Metals, 2021, 46(7): 229-232.
[10]	Jia Dongsheng, Hong Zhenjun, Wang Xiaohai, Wang Maoqiu, Mao Lu, Zhang Ruijun. Effect of nitrogen-methanol atmosphere on hydrogen-induced fracture of45CrNiMoVA high strength steel [J]. Heat Treatment of Metals, 2021, 46(7): 233-237.
[11]	Lü Jing, Yang Qiquan, Zhang Qian, Hu Jie, Xu Xin. Cause analysis of cracks in bolt holes of cast steel wheel-mounted brake disc [J]. Heat Treatment of Metals, 2021, 46(7): 238-241.
[12]	Lin Wenqin, Lu Han, Xu Xinjie, Yang Yuanxi, Deng Feng, Wu Jiaxin. Fracture reason analysis and improvement measures of binaural plate screw [J]. Heat Treatment of Metals, 2021, 46(7): 249-253.
[13]	Ji Guoqiang, Ge Guiming, Yu Lijuan, Zhong Jizhi. Analysis on cracking of 50CrV4 steel washer [J]. Heat Treatment of Metals, 2021, 46(7): 254-257.
[14]	Chen Shuisheng, Feng Mang, Yang Zhibo. High temperature formability and microstructure of 7075-T6 aluminum alloy [J]. Heat Treatment of Metals, 2021, 46(6): 191-194.
[15]	Jiao Li, Shang Haikun, He Jianfeng, Zhao Yingjun, Zhang Weimin, Li Weimin, Zhou Lanmei. Fracture failure analysis of 42CrMo steel high strength bolts for diesel engine [J]. Heat Treatment of Metals, 2021, 46(6): 245-249.