With the widespread application of stainless steel pipes, people’s requirements for them are getting higher and higher, and the processing technology has become more diversified. Pickling is one of the processing technologies. Do you know why stainless steel pipes after pickling will have a hydrogen embrittlement reaction?
This is because hydrogen has a peeling effect on the oxide scale when the stainless steel pipe is pickled, and it also diffuses into the inside of the steel embryo matrix and then gathers at impurities or pores, which will lead to an increase in internal stress, a decrease in the plasticity of the steel, and an increase in the brittleness of the steel. This effect is called hydrogen embrittlement. Hydrogen embrittlement is mainly affected by the diffusion rate of hydrogen atoms.
1. The diffusion rate of hydrogen in sulfuric acid solution is much faster than that of hydrogen in hydrochloric acid solution.
2. If the pickling temperature is increased, the diffusion rate of hydrogen will increase sharply, and if the pickling concentration is increased, the diffusion rate of hydrogen will not increase much, so try not to pickle at low concentration and high temperature.
3. If there are inclusions such as hydrogen sulfide, carbon dioxide, and arsenic in the process of pickling stainless steel pipes, the diffusion rate of hydrogen atoms will increase, which will increase the possibility of hydrogen embrittlement.
Post time: Sep-12-2024