A kind of steel for nuclear power pressure-bearing equipment and its manufacturing method

Abstract

The invention discloses steel used for nuclear power pressure-bearing equipment and a manufacturing method thereof. The steel comprises the following chemical components by weight: 0.12%-0.18% of C; 0.15%-0.35% of Si; 1.20%-1.65% of Mn; less than or equal to 0.015% of P; less than or equal to 0.010% of S, 0.50%-0.85% of Ni; less than or equal to 0.15% of Cr; 0.020%-0.050% of Al; less than or equal to 0.02% of V; less than or equal to 0.02% of Ti, and the balance Fe and unavoidable impurities. At the same time, non-metallic inclusions in the steel are controlled, and A, B, C and D impurities are guaranteed less than or equal to grade 1.5. The manufacturing method mainly includes steel smelting, rolling, as well as quenching and tempering treatment. Through further optimization of the chemical components, a heat treatment process, and reduction of gas and non-metallic inclusions in steel, the method enables the mechanical properties of a steel plate to be maintained at a high level under a heat treatment state, a simulated post-weld heat treatment state, and a 200DEG C high temperature state, so that the steel plate completely meets the technical index requirements. Meanwhile, the 0DEG C impact absorption energy is still maintained at a high level, and good matching of steel plate strength and toughness is reflected, so that the steel provided in the invention is completely suitable for nuclear power pressure-bearing equipment.

Description

technical field [0001] The invention belongs to the field of ferrous metal materials, in particular to steel for nuclear power pressure-bearing equipment and a manufacturing method thereof. Background technique [0002] With the rapid economic development of all countries in the world, nuclear energy, as a clean, safe and stable energy source, has been paid more and more attention by all countries. It has become a trend to use nuclear energy safely and vigorously develop nuclear power. The application of nuclear power technology has also made considerable progress. It has developed from the original "second generation" technology to the current "second generation plus" and "third generation" technology, which has greatly improved the safety performance. [0003] Among the many nuclear power units built according to different nuclear power technologies, steel for nuclear power pressure equipment plays a pivotal role as a supporting material for nuclear reactor pressure vessel...

AI Technical Summary

Problems solved by technology

However, after simulated post-weld heat treatment, the strength of the steel plate drops significantly, especially the tensile strength can no longer meet the index requirements; at 200°C, the strength of the steel plate, especially the yield strength, drops more obviously, indicating that the high temperature resistance of this steel is relatively low. Low, can no longer meet the needs of nuclear power key equipment construction

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