Steel plate smelting method for improving high heat input welding performance

Abstract

The invention discloses a steel plate smelting method for improving high heat input welding performance. The method comprises the following process flows of converter steel smelting, ladle furnace refining, vacuum furnace refining and continuous casting; and steel comprises the following chemical components in percentage by mass: at most 0.10% of C, 0.1-0.3% of Si, 1.3-1.7% of Mn, at most 0.015% of P, at most 0.005% of S, 0.01-0.12% of Ti, at most 0.5% of Ni, at most 0.5% of Cu, at most 0.3% of Cr, at most 0.3% of Mo, 0.0001-0.005% of Mg, 0.0005-0.002% of B, 0.005-0.025% of Al, 0.001-0.003% of Ca, at most 0.005% of N, at most 0.005% of O and the balance of Fe. A proper deoxidizing agent adding sequence is adopted, the oxygen content is precisely controlled, small and dispersed nano-level occluded foreign substances are formed in molten steel, and the growth of austenite crystals in a welding heat affected zone is effectively pinned, thus the requirements for steel plates for high heat input welding can be met.

Description

technical field [0001] The invention belongs to the technical field of metallurgy and relates to a steel plate smelting method for improving the welding performance of large heat input. technical background [0002] In the fields of shipbuilding, construction, pressure vessels, oil and gas pipelines and offshore platforms, in order to improve the welding efficiency of engineering structures, single-sided submerged arc welding, gas-electric welding, electroslag welding and other high-energy welding technologies with better welding efficiency have been adopted successively. use. The ensuing problem is that the strength and toughness of the welding heat-affected zone decrease significantly with the increase of the welding line energy. Therefore, preventing the deterioration of the performance of the heat-affected zone during the welding process is the key to the development of high-energy-input welding steels. [0003] Studies have shown that one of the measures to improve th...

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Problems solved by technology

Chinese patent ZL 200710052135.2 "A large input energy welded high-strength marine steel plate and its manufacturing method" adopts Ti 2 o 3 、Al 2 o 3 Particle pinning is conducive to stable existence at high temperatures in welding thermal cycles, but these particles have a large diameter and cannot well inhibit the growth of austenite grains

Chinese Patent CN 102191429 A "A Method for Improving the Welding Performance of Thick Steel Plates with Large Energy Input", Chinese Patent CN 102191356 A "Method for Controlling Inclusions of Thick Steel Plates for Large Control method of nano-precipitates in thick steel plate" using MgO particles for pinning, which can not only exist stably at a high temperature of 1400°C in welding heat cycle, but also form nano-scale inclusions, but it is carried out in a 50Kg vacuum induction furnace, which cannot Trial for industrial production

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