Steel for high-pressure pipeline valve and manufacturing method thereof

Abstract

The invention discloses steel for a high-pressure pipeline valve and a manufacturing method of the steel. The steel for the high-pressure pipeline valve comprises components in percentage by weight as follows: 0.19%-0.23% of C, 0.15%-0.25% of Si, 0.95%-1.10% of Mn, smaller than or equal to 0.30% of Cr, smaller than or equal to 0.40% of Cu, smaller than or equal to 0.020% of S, smaller than or equal to 0.020% of P, smaller than or equal to 0.40% of Ni, smaller than or equal to 0.12% of Mo, 0.010%-0.040% of Ti, smaller than or equal to 0.03% of V, smaller than or equal to 0.02% of Nb, 0.015%-0.025% of Al, smaller than or equal to 15*10<-6> of O, smaller than or equal to 90*10<-6> of N and the balance of Fe and inevitable impurities. Through content control of carbon and manganese elements, the mechanical property requirements of steel are guaranteed, meanwhile, the content of residual elements is controlled, the material welding property requirement is guaranteed, the fatigue strength of steel is enhanced, and the valve stability is guaranteed. Through control of molten iron (or pig iron) mixing proportion, furnace slag refining amount, VD (vacuum degassing) furnace operation and reinforced water gap protection and casting effect, titanium is added for nitrogen fixation, and the nitrogen content can be controlled below 90 ppm.

Description

technical field [0001] The invention belongs to the technical field of metallurgy, and in particular relates to a steel used for manufacturing high-pressure pipeline valves and a manufacturing method thereof. Background technique [0002] The valve mainly plays the role of cutting and throttling on the pipeline. The performance of high-pressure valves directly affects the reliability, safety, work efficiency and service life of the entire system. It is especially important in systems that require frequent pressurization and decompression. The main failure causes of high-pressure valves are cavitation and erosion wear, and there are many factors that affect cavitation and erosion, mainly including the mechanical properties of materials, hydrodynamic factors and environmental influences. In order to improve the ability of high-pressure valves to resist erosion and wear, steel for high-pressure pipeline valves generally has the following requirements: high material hardness; ...

AI Technical Summary

Problems solved by technology

[0005] The invention aims at the use requirements of steel for high-pressure pipeline valves, develops and produces steel for high-pressure pipeline valves, improves the preparation method by rationally designing the steel composition, solves the problems of steel composition design, performance, structure, and surface quality, and provides a steel that can satisfy Steel for high-pressure pipeline valves required by users and manufacturing method thereof

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