Analysis of the causes of weld cracking in 304 equipment?
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This post was last edited by sunmoonforest on 2018-11-22 14:46 During the annual inspection of the company's equipment, cracks were found in the same welds of multiple pieces of equipment of the same type. After material analysis, hardness testing, and medium CL ion testing, there were no obvious problems. I wonder if the cracking was caused by a combination of factors? Please give me some advice from all the equipment experts! Equipment design parameters: design temperature: Shell side 130°C, jacket 143°C. design pressure: Shell side 0.25Mpa, jacket 0.33Mpa. shell side medium: Polyethylene, steam, hot air, jacketed medium: Low pressure steam. Working conditions (actual): Shell side working temperature 115°C, jacket: 130°C. Equipment material: 304, the thickness of the nipple is 8mm, and the thickness of the cone is 12mm.
If only the weld seam leaks, the problem should appear in the welding, welding material, welding groove, full penetration, whether there are pores, inclusions, cracks, etc.
I can’t see some of the pictures. What are the specific locations? If cracks appear on multiple units at the same location, it’s a commonality. It doesn’t seem to be a material problem.
Sometimes pictures cannot be uploaded and I have to delete them again and upload them again.
It is not all weld leakage, there are cracks in the welds, and there are also cracks in the base metal in the heat affected zone of the welds, some cracking along the direction of the welds, and some cracking vertically. Other parts were not detected, so there was a problem with this position alone.
During the annual inspection of the company's equipment, cracks were found in the same welds of multiple pieces of equipment of the same type. After material analysis, hardness testing, and media CL ion testing, there were no obvious problems.
The base material has been spectrum tested and there is no problem with the material.
The expression is not very accurate, it should be the same weld and heat affected zone.
See the upper weld pointed by the red line in the design drawing. https://bbs.hcbbs.com/thread-2125319-1-1.html
Personally, I think we should check the welding process and welding records of the container. It may be a problem with the welding process.