800MPa seamless steel pipe for marine drilling platform pile leg containing rare earth and manufacturing method of 800MPa seamless steel pipe

Abstract

The invention relates to an 800MPa seamless steel pipe for pile legs of an ocean drilling platform containing rare earth and a production method thereof. The raw material of the seamless steel pipe is composed of 90% by weight of blast furnace molten iron and 10% of heavy steel scrap; the chemical composition of the tube billet by weight percentage is: C 0.07‑0.13; Si 0.20‑0.40; Mn1.60‑1.80 ; P≤0.015; S≤0.005; Cr 1.70‑1.90; Mo 0.70‑0.90; Ni 0.20‑0.40; ; The balance is matrix Fe and trace impurity elements. The above-mentioned 800MPa seamless steel pipe has the advantages of low cost, low production difficulty and excellent mechanical properties.

Description

technical field [0001] The invention relates to the field of ferrous metal smelting and metal pressure processing, in particular to an 800MPa seamless steel pipe for pile legs of an ocean drilling platform containing rare earth and a production method thereof. Background technique [0002] The seamless steel pipes used for pile legs of offshore drilling platforms have been in service for a long time in harsh environments such as formation creep, high-pressure seawater erosion and corrosion. Therefore, the steel pipes are faced with destructive accidents such as corrosion cracking and fatigue failure. These two forms of damage are usually catastrophic, and both will cause huge losses in terms of people, property, and materials. In order to adapt to the harsh service conditions of the marine environment, a rare earth-containing offshore drilling platform pile is specially developed. The legs are made of 800MPa seamless steel pipe. [0003] After retrieval, similar background ...

AI Technical Summary

Problems solved by technology

These two forms of damage are usually catastrophic, and both will cause huge losses in terms of people, property, and materials. In order to adapt to the harsh service conditions of the marine environment, a rare earth-containing offshore drilling platform pile is specially developed. 800MPa seamless steel pipe for legs

[0003] After retrieval, similar background technologies include: "Steel for offshore drilling platforms with fatigue strength ≥ 600MPa and its production method" (patent application number: 201410197337.6), which has the following problems and disadvantages: due to the precious element Cu contained in the steel, the production cost Relatively high, the production process is relatively complicated, and the production difficulty is relatively large;

[0004] After searching, there is a similar background technology: "a steel for offshore drilling platform" (patent application number: 201210435768.2), which has the following problems and shortcomings: because the steel contains precious element Cu, the production cost is relatively high;

[0005] After searching, the similar background technology also has: "A preparation method of steel for offshore drilling platform" (patent application number: 201210435770.X), which has the following problems and shortcomings: because the steel contains precious element Cu, the production process is relatively Complex and relatively difficult to produce

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