The three elements of solid solution treatment for cold drawn tubes are temperature, holding time and cooling rate. The solution treatment functions of high-precision cold-drawn tubes are as follows:
1. For raw materials, it is particularly important to make the structure and composition of the cold-drawn pipe uniform, because the rolling temperature and cooling rate of each section of the hot-rolled pipe are different, resulting in inconsistent structure. At high temperature, the atomic activity is enhanced, the σ phase dissolves, the chemical composition tends to be uniform, and a uniform single-phase structure is obtained after rapid cooling.
2. Eliminate work hardening for continued cold working. Through solution treatment, the distorted crystal lattice is restored, the elongated and fractured grains are recrystallized, the internal stress is eliminated, the tensile strength of the steel wire is reduced, and the elongation is increased.
3. Restore the inherent corrosion resistance of cold-drawn pipes. Due to the carbide precipitation and lattice defects produced by cold working, the corrosion resistance of high-precision cold-drawn tubes is reduced. After solution treatment, the corrosion resistance of the high-precision cold-drawn tube returned to a good state.
https://www.ht-tube.com/