Low-cost and high-crack-arrest extra-thick steel plate and manufacturing method thereof

Abstract

The invention discloses a low-cost and high-crack-arrest extra-thick steel plate and a manufacturing method thereof. The low-cost and high-crack-arrest extra-thick steel plate comprises the followingcomponents of, in percentage by weight, 0.050%-0.080% of C, less than or equal to 0.15% of Si, 1.65%-1.95% of Mn, less than or equal to 0.013% of P, less than or equal to 0.003% of S, less than or equal to 0.20% of Cu, less than or equal to 0.20% of Ni, less than or equal to 0.15% of Mo, 0.006%-0.015% of Ti, 0.015%-0.030% of Nb, less than or equal to 0.0050% of N, 0.035%-0.065% of Al, 0.0010%-0.0040% of Ca and the balance Fe and inevitable impurities. According to the low-cost and high-crack-arrest extra-thick steel plate and the manufacturing method thereof, a component system of ultra-low C,low Si, high Mn, Nb microalloying and ultra-micro Ti treatment is adopted, the high-crack-arrest steel plate with excellent weldability is obtained through a TMCP process, wherein the yield strengthof the steel plate is larger than or equal to 460 MPa, the tensile strength of the steel plate is 570-720 MPa, Charpy impact energy (single value) at the temperature of 50 DEG C below zero is larger than or equal to 100 J, and the Kca (10 DEG C below zero) is larger than or equal to 8000 N/mm <3/2>.

Description

technical field [0001] The invention relates to a low-cost, high-crack-arrest extra-thick steel plate and a manufacturing method thereof, which are especially suitable for large-scale VLCC container ships, large-scale offshore wind power pile legs, offshore platforms (including offshore engineering machinery, marine floating cranes) and cross-sea bridge steel Fabrication of structures. 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 important properties of...

AI Technical Summary

Problems solved by technology

Japan's Sumitomo Metal successfully developed a thick steel plate FCA with excellent weldability, fatigue crack growth resistance, and a yield strength of 355MPa. 2001 (2001) No.190, P507; まてりあ Vol.43 (2014) No.2, P148], achieved good practical results, and achieved mass supply, but the steel plate Development of High Crack Arrest Properties Not Involved in Extra-Thick Steel Plates

[0004] 还有如中国专利ZL201410300713.X、ZL201310244712.3、 ZL201310244706.8、ZL201310124065.2、ZL201310244713.8、 ZL201210209637.2、ZL201410815614.5及申请号201710183350.X所公开的系列可以大热输入焊接各类低温钢板 In order to ensure the low-temperature toughness of the heat-affected zone of large heat input welding, a certain amount of precious alloying elements Cu and Ni are added to the steel. Although the welding performance of the steel plate with super large heat input is good, the toughness of the welding heat-affected zone has certain fluctuations, and the manufacturing cost of the steel plate It is also higher, and it does not involve the crack arrest characteristics of extra-thick steel plates

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