High-performance brittle crack resistant nuclear power pressure-bearing device steel and method for manufacturing same

By controlling the chemical composition and optimizing the process, high-performance steel for nuclear power plant pressure equipment with brittle crack resistance was prepared, solving the problems of insufficient strength, toughness and brittle crack resistance in the existing technology, and realizing low-cost large-scale production.

CN120700418BActive Publication Date: 2026-07-03ANGANG STEEL CO LTD +1
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Patent Information

Application Number
CN202511149848.5
Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Filing Date
2025-08-18
Publication Date
2026-07-03
Estimated Expiration
2045-08-18

AI Technical Summary

Technical Problem

Existing steels used in nuclear power plant pressure equipment cannot simultaneously meet high requirements in terms of strength, toughness, and resistance to brittle cracks, and their production costs are high, making them unsuitable for large-scale production.

Method used

By strictly controlling the chemical composition, including the proportions of elements such as C, Si, Mn, Cr, Cu, Ni, Mo, and V, and combining appropriate smelting, heating, rolling, and heat treatment processes, steel for nuclear power pressure equipment with excellent resistance to brittle cracks is prepared, including steps such as billet heating, multi-stage rolling, quenching, and tempering.

Benefits of technology

The produced steel plates exhibit excellent mechanical properties, tensile strength, and low-temperature toughness under quenching and tempering and simulated post-weld heat treatment conditions, meeting the safety requirements of nuclear power units while reducing production costs.

✦ Generated by Eureka AI based on patent content.

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Abstract

This invention discloses a high-performance steel for nuclear power plant pressure-bearing equipment resistant to brittle cracking and its manufacturing method. The chemical composition is: C 0.16~0.24%, Si 0.20~0.40%, Mn 1.25~1.60%, P≤0.010%, S≤0.005%, Cr 0.25~0.45%, Cu 0.25~0.40%, Ni 0.30~0.50%, Ca 0.005~0.008%, Mo 0.65~1.25%, V 0.04~0.08%. The manufacturing method includes smelting, continuous casting, hot rolling, and heat treatment. The steel plate, with a thickness of 30-120 mm, undergoes quenching and tempering and simulated post-weld heat treatment. At room temperature, its tensile yield strength is ≥620 MPa and tensile strength is ≥770 MPa; at 360℃, its tensile yield strength is ≥518 MPa and tensile strength is ≥618 MPa; its impact absorption energy at -40℃ is above 195 J; its non-ductile transition temperature is ≤-52℃; and its grain size is ≥8.5. This invention possesses excellent mechanical properties and resistance to brittle cracking, fully meeting the requirements for steel used in pressure-bearing equipment of nuclear power units.
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Citation Information

Patent Citations

  • Steel for nuclear power pressure equipment with high toughness, high ductility and low irradiation embrittlement and making method thereof

    CN101892442A

  • Steel for nuclear power pressure equipment at temperature of -50 DEG C and manufacturing method thereof

    CN102181807A

  • Steel for nuclear power pressure-bearing equipment and manufacturing method thereof

    CN103160732A

  • Large-thickness Z-direction easily-welded steel for nuclear power pressure-bearing equipment and preparation method of large-thickness Z-direction easily-welded steel

    CN116732432A

  • Steel for nuclear pressure vessels and manufacturing method thereof

    CN102605296A