A kind of preparation method of martensitic steel pipe

Abstract

The invention discloses a method for preparing a martensitic steel pipe, which comprises the following steps: 1) punching a center hole in a martensitic steel pipe blank, and then piercing; the piercing temperature is 1000-1200°C; 2) piercing the pipe 3) Pickling the annealed tube blank with pickling solution, and then performing phosphating, saponification and lubrication treatment in sequence; 4) Cold rolling the lubricated tube blank to obtain a martensitic steel pipe Finished product; the annealing process in the step 2) includes the following steps in turn: a. Put the steel pipe billet into the furnace, raise the temperature to 750-760°C, and keep it warm for 0.5-1.5h; b. Raise the temperature in the furnace to 770-820°C ℃, treatment for 3-4h; c. lower the temperature in the furnace to 710-730℃, and keep it for 1.5-2.5h; d. lower the temperature in the furnace to 650-700℃, and keep it for 1.5-2.5h; e. , cooled to room temperature. The preparation method is simple and reliable, the martensitic steel pipe is not cracked during the production, and the discarded amount of the tube billet is reduced; the prepared martensitic steel pipe has good quality, low strength and good toughness, and is suitable for further processing.

Description

Technical field [0001] The invention relates to the preparation field of steel pipes, in particular to a preparation method of a martensitic steel pipe. Background technique [0002] Martensitic stainless steel has good mechanical properties, high temperature oxidation resistance and corrosion resistance, so it has a wide range of applications. However, the preparation of martensitic steel pipes is difficult, and the martensitic steel pipes obtained are of poor quality and are not durable. The patent number is The Chinese patent of CN102699103 discloses a preparation method of 20CrMo steel pipe on October 3, 2012. The process steps are short and are beneficial to saving energy consumption. However, during the production process, longitudinal cracks on the inner or outer surface of the steel pipe often occur. It is impossible to carry out subsequent processing, resulting in waste of steel, and the martensitic steel pipe produced has very high hardness and low toughness, and it is ...

AI Technical Summary

Problems solved by technology

[0002] Martensitic stainless steel has good mechanical properties, high temperature oxidation resistance and corrosion resistance, so it has a wide range of applications, but the preparation of martensitic steel pipes is difficult, and the quality of the obtained martensitic steel pipes is poor and not durable. The patent number is The Chinese patent of CN102699103 disclosed a preparation method of 20CrMo steel pipe on October 3, 2012. The process steps are short and beneficial to save energy consumption. However, during the production process, longitudinal cracks often occur on the inner or outer surface of the steel pipe. It is impossible to carry out subsequent processing, resulting in waste of steel, and the obtained martensitic steel pipe has very high hardness and low toughness, so it is difficult to process again