In the process of laser welding of stainless steel, generally need to conduct post-welding heat treatment, especially martensite, ferritic stainless steel, the selection of the correct pre-heat and post-welding treatment is to ensure the quality of laser welding machine. So what is the stainless steel after the heat treatment process?
The influence of post weld heat treatment on tensile strength and creep limit of stainless steel is related to the heat treatment temperature and holding time. The influence of post welding heat treatment on the impact toughness of stainless steel varies with different steel types. Generally, single high temperature tempering or normalizing with high temperature tempering is used in the post welding heat treatment process of stainless steel:
1. Normalizing and tempering at high temperature
For the gas welding welding joint using normalizing and high temperature tempering heat treatment. This is because the grain size of the weld and the heat-affected zone of gas welding is large and needs to be refined, so normalizing treatment is adopted.
2. Single high temperature tempering
However, single normalizing cannot eliminate residual stress, so it is necessary to add high temperature tempering to eliminate stress. Single medium tempering is only suitable for the assembly and welding of large ordinary low carbon steel containers assembled on site. The vast majority of occasions are to choose a single high temperature tempering. The heating and cooling of heat treatment should not be too fast.
Post-weld heat treatment can eliminate the residual stress of slack welding of stainless steel. Stable structure shape and size, reduce distortion; Improve the plasticity of weld metal; Improve fatigue strength; Improve the ability to resist stress corrosion; To prevent the occurrence of delayed crack, so the heat treatment of stainless steel after welding is very important.
On 2018-08-08 11:45:46
