The aging phenomenon of stainless steel pipe means that the material of stainless steel pipe changes with the passage of time. The hardness of stainless steel increases over time, which is age hardening. Aging phenomenon means more than hardening. Hardness and strength are obvious characteristics of stainless steel, so we call it aging to mean hardening. Due to the phenomenon of age hardening, the creation of duralumin is available. Duralumin is called aluminum alloy 2000 series here, and the original creation is very good. The age hardening of stainless steel pipes can be understood as follows. The alloy elements that should accumulate during the heat treatment of the stainless steel pipe will not accumulate due to the rapid cooling, but are forcibly dissolved in the steel pipe, which is a solution treatment.

The solution-treated stainless steel pipe is in an unstable condition, and the alloy elements inside it may accumulate in an attempt to recover the stable condition. With the passage of time, the alloy elements gradually accumulate, making the relative sliding between the alloy grids more and more difficult, that is, the hardness of the alloy is getting higher and higher. From the above process, age hardening can be called accumulation hardening. The aging effect of hardening at room temperature is room temperature hardening. Artificial age hardening is a method of artificially increasing the temperature and accelerating the movement of the atoms of the elements dissolved in the alloy to accelerate the age hardening. This artificial age hardening is also called pile hardening. Aluminum alloys and castings have relevant standards in JIS. T4 indicates that hardening is carried out at room temperature after quenching, and T5 and T6 indicate that the tempering treatment is accumulation hardening.

Stainless steel is called accumulation hardening, which is a kind of steel that is hardened by accumulation. As a term similar to aging, it changes with the passage of time and changes with the passage of time. This is the same as age hardening. Age hardening refers to material changes over time, but in contrast to hardening, it usually refers to poor changes, that is, reduced functionality.