High-strength anti-corrosive steel product and preparation method therefor and application thereof

Abstract

The invention discloses a high-strength anti-corrosive steel product. The high-strength anti-corrosive steel product comprises the following components in percentages by weight: less than 0.02% of carbon, less than 0.5% of silicon, 0.4-0.6% of manganese, less than or equal to 0.015% of phosphorus, less than or equal to 0.01% of sulfur, 9.5-10.5% of chromium, 0.35-0.5% of nickel, 0.2-0.35% of molybdenum, less than or equal to 0.65% of copper, less than or equal to 0.007% of aluminum, less than or equal to 0.15% of titanium, less than or equal to 0.04% of vanadium, less than or equal to 0.12% of niobium, less than or equal to 0.02% of zinc, less than or equal to 0.07% of tungsten, less than or equal to 0.03% of cobalt, less than or equal to 0.04% of tin, less than or equal to 0.02% of lead and the balance of ferrum. The high-strength anti-corrosive steel product disclosed by the invention has the beneficial effects that the content of carbon and sulfur is reduced, the steel tissues are refined, and the molecular structural density of the steel is improved to achieve corrosion resistance and mechanical property; as the tissues of the steel are full, the diffusing speed of steel atoms is increased, chromium in the crystals and in the crystal boundary in a metallographic structure is easy to balance, thereby playing a role of preventing crystal boundary corrosion. Meanwhile, spot corrosion is replaced by uniform tiny corrosion on an integral plane, so that the corrosion rate is delayed; alloys such as molybdenum, nickel and copper alloys are added to form an intermetallic compound, so that the matrix structure is strengthened; crystalline grains can be refined by adding niobium, vanadium and titanium, so that the toughness of a material is further improved.

Description

technical field [0001] The invention relates to the field of steel products, in particular to a high-strength anti-corrosion steel product and its preparation method and application. Background technique [0002] Oil wells and gas wells of crude oil and natural gas containing H2S (hereinafter, oil wells and gas wells are collectively referred to as "oil wells") have the problem of sulfide stress cracking (hereinafter referred to as "SSC") of steel in a humid hydrogen sulfide environment, Therefore, oil well pipes with excellent SSC resistance have become necessary. [0003] The SSC resistance drops sharply as the strength of steel increases. Therefore, in the past, only 110 ksi class (yield strength: 758-862 MPa) steel materials can ensure SSC resistance under general evaluation conditions, that is, under the environment of NACE solution A (NACETM0177-2005) containing 1 bar H2S. And, in most cases, higher strength 125ksi grade (yield strength: 862~965MPa), 140ksi grade (yi...

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Problems solved by technology

However, due to the characteristics of the compatibility of 20CrMo components, it basically does not have anti-corrosion performance, so it can only be used as a general structural part in the parts of ordinary vehicles and machine tools without anti-corrosion requirements, and is not suitable for containing K in coastal oil wells. + 、Na + , Ca 2+ , Mg 2+ Alkaline earth metal ions and Cl - , SO 4 2- Used in the harsh environment of ionic liquids, needs to be improved

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