一种高强度马氏体不锈钢连续油管制造方法
By processing tempered martensitic stainless steel coils into steel strips and employing gas-protected laser welding and multiple heat treatments, the corrosion failure problem of conventional carbon steel and low alloy steel coiled tubing under harsh working conditions has been solved, resulting in the manufacture of high-strength martensitic stainless steel coiled tubing with excellent corrosion resistance and economic efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CHINA NAT PETROLEUM CORP
- Filing Date
- 2022-06-30
- Publication Date
- 2026-07-17
AI Technical Summary
Conventional carbon steel and low alloy steel coiled tubing suffer from significant corrosion failure under harsh conditions such as high temperature, high pressure, high CO2/H2S content, high Cl- content, and formation water with high mineralization, making them unsuitable for field use.
Steel strips are made from tempered martensitic stainless steel coils. High-strength continuous oil pipes are formed by gas-protected laser welding and preheating treatment, combined with medium-frequency induction heating and muffle furnace heating, thereby controlling welding quality and improving the synergistic effect of material composition.
We manufacture high-strength martensitic stainless steel continuous tubing with a yield strength ≥552MPa, tensile strength ≥689MPa, and elongation ≥25%, which has good resistance to CO2 corrosion and Cl- pitting corrosion, extends service life, and is economical.