Seamless Steel Pipe Cracks

تاريخ:2018-04-04 رأي:2212
Seamless steel pipe cracking is as follows:.
1. The morphology of hot-rolled and cracked seamless steel tube was observed under scanning electron microscope, and obvious cracks were observed in the middle of the fracture.
2. Further observation of hot-rolled and cracked seamless steel tube cracks and their ends revealed that there were obvious oxidized particles near the cracks, and there were intra-crystalline cracks at the crack tip, and a complete polygonal ferrite morphology was present near the crack.
3. The characteristics of oxidized particles in the vicinity of 30 um of the crack are closely related to the original defects of the continuous casting billet. Continuous heating of the billet in the heating furnace causes the elements near the cracks to be oxidized to form a thicker oxidized point layer. This defect is eventually found. Inherited into the final hot roll.
4. It is found that there are obvious cracks and oxidation bands in the center of the thickness and 1/4 of the thickness, and there are also oxidized particles near the crack.

There are different internal cracks in the whole volume of the broken coils. The cracks mainly exist near the middle of the coils, showing continuous topography and higher cracking risk.
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