Low alloy high-strength steel plate capable of being welded in large energy input and method of producing the same

Abstract

The invention provides a high strength low alloy steel plate suitable for high heat input welding and is characterized in that the chemical composition (wt percent) of steel comprises 0.04 percent to 0.16 percent of C, 0.10 percent to 0.50 percent of Si, 0.40 percent to 1.8 percent of Mn, 0.020 percent to 0.050 percent of Nb, 0.006 percent to 0.030 percent of Ti, 0.0030 percent to 0.010 percent of N, 0.015 percent to 0.060 percent of Al and the rest, Fe and other inevitable impurities; meanwhile, C+Mn/6+Si/24+Ni/40+Cr/5+Mo/4+V/14 is less than or equal to 0.45 percent and the total amount of Ti and the total amount of N are that [Ti percent]T is more than or equal to 2.667[N percent]T-0.004667 percent; moreover, Ti microalloying is adopted to ensure that the Ti/N ratio in the second sort of particle generated ranges between 2.4 and 3.2. The manufacture method of the steel plate adopts austenite recrystallization zone and austenite non-recrystallization zone rolling and forced water cooling after rolling; moreover, when the steel plate is under 50 KJ/cm to 150 KJ/cm high heat input welding, the welding heat affected zone has excellent toughness. The invention has the advantages of simple production process, low cost and wide applicability.

Description

technical field [0001] The invention belongs to the field of low-alloy steel manufacturing, in particular to a low-alloy high-strength steel plate that can be welded with large heat input and a manufacturing method thereof. Background technique [0002] Before the present invention, there have been some public reports of steels for large heat input. Such as the patents declared by Wuhan Iron and Steel Company "Large input energy welding non-quenched and tempered high toughness low temperature steel and its manufacturing method" (public number CN1338528A) and "large input energy low welding crack sensitivity series steel and its production method" (public number CN1396294A ). The common feature of these technologies is the addition of B, the use of BN and Ca or Re oxides to inhibit the grain growth of the heat-affected zone and improve the performance of the heat-affected zone. However, the addition of B often produces side effects. B is easily segregated at the grain bound...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a low-alloy high-strength steel plate that can be welded with large input energy and its manufacturing method, so as to solve the problems of reduced toughness of the base metal, inability to meet the requirements of large input energy and difficult control in production