High-strength and high-toughness super-thick quenched and tempered hydroelectric steel plate and preparation method thereof

Abstract

The invention discloses a high-strength and high-toughness super-thick quenched and tempered hydroelectric steel plate and a preparation method thereof. The steel plate comprises the following chemical components: 0.09-0.11% of C; 0.10-0.20% of Si; 0.70-0.90% of Mn; less than or equal to 0.010% of P; less than or equal to 0.003% of S; 0.20-0.40% of Ni; 0.30-0.40% of Cr; 0.85-0.95% of Mo; 0.25-0.35% of Cu; 0.02-0.04% of Nb; 0.010-0.020% of Ti; 0.035-0.055% of Als; 0.0004-0.0010% of B; less than 50 ppm of N; and the balance of Fe and inevitable impurities. Meanwhile, it is guaranteed that Pcm=C+Si / 30+(Mn+Cu+Cr) / 20+Ni / 60+Mo / 15+V / 10+5B is less than 0.26%; Ceq(%)=C+Mn / 6+Si / 24+Ni / 40+Cr / 5+Mo / 4 V / 14 is less than 0.56%. The thickness of the high-strength and high-toughness super-thick quenched and tempered hydroelectric steel plate is larger than 100 mm, the tensile strength is larger than or equal to 780 MPa, the yield strength is larger than or equal to 690 MPa, and the transverse Kv-70 DEG C is larger than or equal to 100 J.

Description

Technical field [0001] The present invention belongs to the field of alloy steel, which relates to a high-strength toughness ultra-thick mass-touched hydropower steel plate and a manufacturing method thereof. Background technique [0002] Japan's major steel companies have taken the use of B low-carbon low alloy steel component system in the 1960s, and developed a temperature steel plate for injection molded 800 MPa. 800MPa-level hydropower steel began to apply in Japan, Europe and China's Tombs. Entering the 21st century, 800MPa-level hydropower steel development in China, truly started to start, and applied to large power stations such as Hohhot Pumping Storage Power Station, Baihe Beach, Udao. [0003] China's 800MPA-grade hydropower steel is mainly steel plates with a thickness of 100 mm, and the strong toughness excellent 800MPA ultra-thick steel plate (thickness> 100mm ~ 200mm) is very high in the technical content of the technical content, less in China. [0004] China'...

AI Technical Summary

Problems solved by technology

Using continuous casting slabs, "normalizing + quenching + high temperature tempering" to produce thick steel plates with a maximum thickness of 115mm, the maximum thickness is limited, and the process flow is long

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