The austenitic stainless steel seamless pipe
is softened by solution treatment. Usually, the stainless steel seamless pipe is heated to a temperature range of 950-1150 ° C and kept for a period of time, so that the carbides and various alloy elements in the material are completely uniform. Dissolved in the austenite structure, and then rapidly quenched and cooled by water, carbon and some other alloying elements will not have time to precipitate, so that a high-purity austenite structure can be obtained, which is called solid solution treatment.
One is to keep the structure and composition of the stainless steel seamless pipe uniform, which is very important for raw materials, because the rolling temperature and cooling speed of each section of the hot-rolled wire rod are different, which can easily lead to inconsistent structure. At high temperature, the atomic activity will be intensified, the σ phase will dissolve, and the chemical composition will tend to be uniform. After rapid cooling, a highly uniform single-phase structure can be obtained.
is to eliminate work hardening, which facilitates continued cold working. After solution treatment, the distorted lattice will recover, the elongated and broken grains will recrystallize, the internal stress will also be eliminated, the tensile strength of the stainless steel seamless tube will decrease, and the elongation will increase.
The third is to restore the inherent corrosion resistance of stainless steel seamless pipes. Because cold working causes carbide precipitation and lattice defects, the corrosion resistance of stainless steel seamless pipes is reduced. After the solution treatment, the corrosion resistance of the stainless steel seamless pipe is restored to the state.