Steel for high strength fastener for marine environment

A marine environment, high-strength technology, applied in the field of steel, can solve problems such as the effect is questionable, and achieve the effect of reducing probability and risk
CN110438398APending Publication Date: 2019-11-12LUOYANG SUNRUI SPECIAL EQUIP
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
LUOYANG SUNRUI SPECIAL EQUIP
Publication Date
2019-11-12

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Abstract

The invention relates to steel for a high strength fastener for a marine environment. The steel is prepared from the following raw materials in percent by weight: 0.08-0.20% of C, 0.10-1.0% of Si, 0.3-1.0% of Mn, less than or equal to 0.005% of S, less than or equal to 0.005% of P, 0.2-1.2% of Cr, 4.5-9.5% of Ni, 0.3-1.0% of Mo, less than or equal to 0.15% of V and the balance Fe and other inevitable impurities. The hydrogen diffusion coefficient D of the steel is smaller than or equal to 10<-8>mm<2> / s. A hydrogen trap type of the steel is a reversible hydrogen trap, and the hydrogen escape activation energy Ea is smaller than 30 kJ / mol. Starting from an essential attribute design of a material, the average hydrogen content in the steel is reduced, and process and influence of hydrogen atoms taking part in hydrogen induced delayed fracture in an irreversible hydrogen trap are eliminated, so that the hydrogen induced delayed fracture problem of the high strength fastener for the marineenvironment is controlled effectively.
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Description

technical field

[0001] The invention relates to the technical field of steel materials, in particular to a steel for high-strength fasteners used in marine environments. Background technique

[0002] Fasteners, as connecting parts, are widely used in marine engineering equipment, and usually face complex and harsh environmental media such as marine atmosphere and seawater media. However, with the fastener strength grade (tensile strength R m >1000MPa), under the action of stress, the hydrogen-induced delayed fracture susceptibility of high-strength fasteners increases, resulting in the loss of plasticity of the material and unexpected fracture, which endangers the safe operation of the equipment. Therefore, the hydrogen-induced delayed fracture control technology of high-strength fasteners has been widely concerned and valued.

[0003] At present, domestic and foreign researches on steels for anti-hydrogen-induced delayed fracture fasteners mainly focus on the chemical ...

Claims

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