Deformation straightening issue of stainless steel pipes after solution treatment
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After solution treatment of stainless steel pipes, the bent pipes need to be straightened. What are the common straightening processes used? What is the typical magnitude of the residual stress it introduces?
Our company has never measured the stress that can be generated during the straightening of steel pipes. Straightening refers to the steel pipe straightening machine – it has many rollers, and there are many products available for sale on Baidu
You may want to look into it further; test data show that for stainless steels with different compositions, the residual stress resulting from straightening varies, but it is generally in the range of 80–120 MPa.
I’m not aware of the specific standards, but you can refer to the book on stress corrosion of stainless steel written by Lu Shiying
Heat exchange tubes are usually straightened using horizontal multi-roller straightening machines (6–12 rollers are common); these rollers can be made of metal or nylon. The bent parts resulting from solution treatment generally have large radii of curvature, and these issues can be resolved through pre-straightening and final straightening Most manufacturers in China do not test the stress generated by straightening, and this is also not mandated by standards 14976 and 13296!
The following literature is about a heat exchange tube that suffered from stress corrosion cracking; it has been shown that the source of stress for this corrosion was the residual stresses remaining after the tube was straightened, for reference.
The yield strength of stainless steel varies depending on the type of steel and its surface condition; it depends on what type of steel is being straightened