Why does 304 stainless steel tube crack?
The austenitic stainless 304 stainless steel tube has a CWI of 0.34. This makes it susceptible to phase changes and the formation of a martensitic structure when deformed. The martensitic structure and residual stress in pipes increase as the amount of deformation increases.
Steel strip can influence the quality of the end product. Welding pipes made of stainless steel are usually produced from furnace strips that have different copper content. Low copper materials offer a lower elongation while medium or high copper contents provide a higher elongation for comparatively higher costs. Medium copper materials have been chosen due to the price competition on the market. They are also more cost-effective.
Longitudinal cracks on 304 Stainless Steel Square Tubes: Causes and effects
The cause of longitudinal cracks in hot-dip seamless steel tubes can be due to a variety of factors including the material used or issues with the process. Longitudinal cracks can be caused by poor plasticity, insufficient annealing and residual stress from cold drawing.
After cold drawing, hot-dip galvanized seamless tubes experience residual stress. The tensile stress near the pipe's outer surface in both tangential as well as axial direction is caused by these stresses. These stresses are significant and can play an important role in developing longitudinal cracks.
Square tubes are made of 304 stainless and the residual stress varies depending on production methods, drawing techniques, and products. The residual stress in empty drawn tubes is higher than that of those drawn with short core rods, according to measurements on site. The residual stresses of empty drawn tubes can be up to 2-3 times greater than the ones in pipes that are drawn using short core rods.
Longitudinal cracks are primarily caused by the higher residual stress within square stainless steel tubes. It is advised to reduce the residual stress in drawn empty tubes. To minimize cracks or longitudinal cracks, choose high-quality stainless steel 304 tubes from reliable sources.
Whatsapp: +8615822676888
Email: sales1@tedaganghua.com
评论
发表评论