Full
Outline
Aiming at the cracking phenomenon of thick-gauge HSLA steel plate coils rolled by Hot Rolled Strip Steel Mill of Angang Steel Co., Ltd. after being used for tube making, composition and process analysis were conducted, and it was determined that the low charpy impact test result was the cause of the cracking. Using optical microscopy analysis, thin film analysis and replication method to test and analyze the cracking specimen, it was found that coarse second-phase precipitates existed in the plate coil, the overall microstructure was uneven, the grains were coarse and the upper and lower surfaces were asymmetrical, and there were coarse carbides (alloyized cementite) distributed in a chain-like or network-like pattern at the ferrite grain boundaries. Under the combined influence of these factors, the plate coil cracked after being subjected to tube making stress. By improving the composition design, optimizing the thermal regime, rolling temperature, cooling temperature, rolling deformation regime and so on, through the mass production of 6 000 tons of thick-gauge Q345B hot-rolled steel coils, the individual impact and average impact energy values exceeded 180 J. As a result, the cracking rate of steel coils during pipe manufacturing decreased from 25% to 0, completely resolving the technical challenge of coil cracking in pipe production.
129
44
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |
关闭全屏
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62662699(Operation and Technical Support)
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
