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| Hazard analysis of copper metal pollution on surface of steel pipe |
| ZENG Bing 1，LIU Rongfeng 2，YUAN Jie 2，LIANG Xiaodong 1 |
1. Chongqing Machinery Industry Physical and Chemical Measures Center, Chongqing 400020, China;
2. Petrochina Southwest Oil & Gas Field Materials Branch, Chengdu 610017, China |
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Abstract The unqualified hardness was observed during the field test of base metal of steel pipe for natural gas transmission. Through macroscopic observation, scanning electron microscopy (SEM), metallographic analysis, and microhardness test, it was found that there was copper metal pollution on the surface of steel pipe. Copper metal pollution was essentially belonged to heterometallic inclusion, which was caused by improper smelting operation, incomplete melting of alloy material or falling of foreign metal into gating system. Because the structure and properties of such dissimilar metal inclusions were different from the matrix, there were obvious boundaries with the matrix structure, which would split the continuity of the matrix and reduce the mechanical properties of the material. It would become the stress concentration point in the process of stress, and consequently reduce the service life of the steel pipe.
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Received: 09 November 2020
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| [1] |
SUN Jian-liang, SUN Meng-qian, GUO He-song, JI Jiang, XU Li-pu, PENG Yan. Comprehensive prediction of surface quality of hot-rolled strip with multiple and single defects[J]. Iron and Steel, 2021, 56(1): 51-58. |
| [2] |
WEI Jun-you, ZHAO Wen-bo, CHEN Li, HU Peng, LIU Chong-lin, WAN Xiu-juan. Causes analysis of surface upwarping defects on hot rolled strip[J]. CONTINUOUS CASTING, 2020, 45(6): 48-56. |
| [3] |
WANG Pu，LI Shaoxiang，CHEN Lie，CHEN Xiqing，. Investigation of mold metallurgical behavior under #br# electromagnetic stirring for round bloom[J]. Iron and Steel, 2019, 54(8): 82-89. |
| [4] |
MA Bingzhi1，QI Chunyu1，LOU Decheng1，ZHANG Yudong2. Surface roughness control technology of galvanized sheet skinpass rolling process[J]. Iron and Steel, 2019, 54(10): 91-95. |
| [5] |
ZHANG Jiong，WANG Gan，FAN Hai-ning，ZHANG Li-xin，ZHOU Ya-hui，WANG Quan. Production Practice of Ma Steel Slab Scarfing Machine[J]. , 2018, 43(6): 38-41. |
| [6] |
LIU XU-hui，，YU Qiang，LIU Zhen-yu. Optimization and application of roll gap lubrication in the semi-endless rolling process of CSP line in lianyuan steel[J]. , 2018, 43(5): 13-18. |
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2021, Vol. 39 
