Seamless steel pipes not only require excellent wear resistance, machinability, heat resistance, and high strength and toughness of thick walled seamless steel pipes, but also require molds to have certain corrosion resistance due to the decomposition of gases such as hydrogen chloride, hydrogen fluoride, and sulfur dioxide in the molten state. At present, domestic seamless steel pipe users generally choose 4Cr13 stainless steel.
This study investigated the hardness and microstructure of two types of seamless steel pipe steels after quenching and tempering at different temperatures, and compared and analyzed their polishing performance and corrosion resistance under usage conditions. The results indicate that:
(1) After appropriate heat treatment, both types of experimental seamless steel pipe steels have relatively high hardness. The quenching and tempering hardness of B steel is higher than that of A steel, but both can meet the requirements of seamless steel pipe molds.
(2) Based on the experimental results and the material usage requirements of the mold, a heat treatment process of 1040 ℃ oil quenching+610 ℃ twice tempering is recommended.
(3) The polishing performance of B steel is better than that of A steel under the same state and conditions.
(4) Under the same quenching and tempering process and corrosion conditions, the corrosion resistance of B steel is better than that of A steel, and the average annual corrosion depth is reduced by 34.28% compared to A steel.
