460MPa crack arresting steel plate with low cost and large heat input welding and manufacturing method thereof

Abstract

The invention discloses a 460MPa crack arresting steel plate with low cost and large heat input welding and a manufacturing method thereof. The 460MPa crack arresting steel plate is prepared from thefollowing components in percentage by weight: 0.040% to 0.080% of C, less than or equal to 0.15% of Si, 1.70% to 2.05% of Mn, less than or equal to 0.013% of P, less than or equal to 0.0040% of S, 0.015% to 0.030% of Nb, 0.010% to 0.025% of Ti, less than or equal to 0. 010% of Al, and the balance of Fe and inevitable impurities. According to the invention, ultra-low carbon C, ultra-low Si, high Mn-Nb combined low alloy steel is taken as the basis, the (%Al) is less than or equal to 0.010%, micro Ti treatment is carried out, DI*T cold opening*Vc) / T stop cooling is more than or equal to 11.5 andless than or equal to 26.5, (%Mn)*Ceq is more than or equal to 0.55 and less than or equal to 0.85, TMCP process is optimized, the yield strength of the steel plate is more than or equal to 460MPa, the tensile strength is more than or equal to 550MPa, Charpy impact energy (Single value) at -40 DEG C is more than or equal to 100J, Kca at -10 DEG C) is more than or equal to 6,500N / mm<1.5>, and large heat input welding and ultra-low cost manufacturing can be achieved.

Description

technical field [0001] The invention relates to a low-cost, high-heat-input welded 460MPa crack-arresting steel plate and a manufacturing method thereof. The yield strength of the steel plate is ≥460MPa, the tensile strength is ≥550MPa, and the Charpy impact energy (single value) at -40°C is ≥100J, Kca (-10 o ℃)≥6500N / mm 1.5 , and can achieve large heat input welding and ultra-low-cost manufacturing. Background technique [0002] As we all know, low-carbon (high-strength) low-alloy steel is one of the most important engineering structural materials, widely used in oil and gas pipelines, offshore platforms, shipbuilding, bridge structures, boiler pressure vessels, building structures, automobile industry, railway transportation and machinery under manufacture. The properties of low-carbon (high-strength) low-alloy steel depend on its chemical composition and the process system of the manufacturing process, among which strength, toughness and weldability are the most import...

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Problems solved by technology

[0006] Chinese Patent Application Nos. 201410300713.X, 201310244712.3, ZL201310244706.8, ZL201310124065.2, ZL201310244713.8, ZL201210209637.2 disclose high heat input welding of various low temperature steel plates. It is inevitable to add a certain amount of precious alloying elements Cu and Ni, and it is difficult to guarantee the low-temperature toughness of the heat-affected zone (HAZ) of the steel plate with super large heat input welding, and it does not involve the crack arrest characteristics of the steel plate

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