TMCP type high strength and toughness high fatigue resistance weather-proof bridge steel plate, and preparation method thereof

Abstract

The invention discloses a TMCP type high strength and toughness high fatigue resistance weather-proof bridge steel plate, and a preparation method thereof. The TMCP type high strength and toughness high fatigue resistance weather-proof bridge steel plate comprises, by weight, 0.05 to 0.08% of C, 0.12 to 0.18% of Si, 1.4 to 1.6% of Mn, 0.045 to 0.058% of Nb, 0.01 to 0.02% of Ti, 0.30 to 0.35% of Cu, 0.22 to 0.30% of Cr, 0.45 to 0.55% of Ni, 0.02 to 0.04% of Al, 0.05 to 0.12% of Mo, P<=0.009%, S<=0.005%, and the balance Fe and other unavoidable impurities. The advantages are that: product performance is excellent; the yield strength is larger than 500MPa; -60 DEG C crack-tip opening displacement index is 0.3mm or higher; 10 million time fatigue strength is 170MPa or higher; and corrosion weight loss rate is 3.0g / (m2*h) or lower.

Description

technical field [0001] The application belongs to the technical field of metallurgy, and in particular relates to a TMCP type weather-resistant bridge steel plate with high strength, toughness and high fatigue performance and a preparation method thereof. Background technique [0002] The rapid development of bridge construction technology in my country has promoted the rapid replacement and development of bridge steel. At present, the main span of some new cable-stayed bridges has reached the kilometer level, and ordinary strength bridge steel can no longer meet the force requirements of bridge bars. Q370qD / E high-performance bridge steel has become the mainstream steel grade, and higher performance The Q500qE class has also been applied to national key projects such as the Hutong Bridge and Pingtan Bridge under construction. [0003] High-performance bridge steel needs to have high strength (yield 370MPa and above), high toughness (impact energy not less than 120J), low y...

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Problems solved by technology

[0006] The publication number is CN 106811704 A, which proposes a bridge steel with a yield strength of 500MPa and a low yield ratio bridge steel and its manufacturing method. Its strength level reaches 500MPa, and the steel plate yield ratio is below 0.85, but its impact absorption energy is limited to - The measured value at 40°C, and its product performance does not involve fatigue strength and corrosion resistance

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