| 摘要: |
| 在役焊接过程中，管内流动介质的快速冷却，易使接头出现氢致裂纹。对20#管线钢在不同冷却条件和不同焊 接线能量下的HAZ的组织性能进行了模拟研究。结果表明，在流动水冷却下，HAZ出现较多的贝氏体、马氏体和 M-A组元等不平衡组织,使得HAZ的硬度高达330HvN5，性能最差。采用大的线能量焊接，形成较多的上贝氏体和 粒状贝氏体组织，对改善接头性能有利。因此，在避免烧穿的前提下增大焊接线能量或减小管内介质的冷却能力， 减少高硬度不平衡相的形成，可以降低HAZ氢致开裂敏感性。 |
| 关键词: 20#管线钢 运行管线 在役焊接 显微组织性能 氢致开裂 |
| DOI： |
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| 基金项目:中国石油大学(华东)博士科研基金资助项目(Y040312)和博士研究生创新基金资助项目(B2005 - 3) |
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| Research on microstructure and property of HAZ of 20 # pipeline steel in-service welding |
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JIN Hai-cheng, WANG Yong, HAN Bin, DONG Li-xian
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(College of Mechanical and Electronic Engineering in China University of Petroleum，Dongying 257061，Shandong Province， China )
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| Abstract: |
| Because of the fast cooling of flowing medium, the hydrogen cracking occurs easily under in-service welding. The simulation research of 20 pipeline steel in different cooling conditions and different heat input was carried out. The results show that there is more unbalance microstructure of Bainite, Martensite and M-A form under flowing water-cooling, which makes the hardness reach 330 HvNs in HAZ, and the property is worst. With large welding heat input, more upper Bainite and granular Bainite form, which is benefit to improve the property of HAZ. The increase of heat input or reducing cooling capacity of medium and the formation of large hardness and unbalance microstructure can lower the susceptibility of hydrogen cracking. |
| Key words: 20# pipeline steel running pipeline in-service welding microstructure property hydrogen cracking |
