Steel for composite microalloyed welding wire and preparation method thereof

Abstract

The invention provides steel for a composite microalloying welding wire and a preparation method thereof. The steel is characterized by comprising the following chemical components in percentage by weight: no less than 0.06% and no more than 0.15% of C, no less than 0.81% and no more than 1.15% of Si, no less than 1.40% and no more than 1.85% of Mn, no less than 0.08% and no more than 0.15% of Ni, no less than 0.05% and no more than 0.15% of Cr, no less than 0.05% and no more than 0.15% of Mo, no less than 0.008% and no more than 0.012% of Ti, no less than 0.006% and no more than 0.030% of V, no less than 0.015% and no more than 0.025% of Nb, no less than 0.0005% and no more than 0.0030% of B, no more than 0.025% of S, no more than 0.025% of P, no more than 0.005% of O and the balance of Fe. The preparation method comprises the following steps of converting, ladle bottom argon blowing, LF refinement, fully-protected continuous casting, hot rolling and STELMOR cooling. The composite alloying provided by the invention is beneficial to refine molten drops, stabilize current and enhance the weld quality, and is beneficial to enhance the weld strength.

Description

technical field [0001] The invention belongs to the field of iron and steel materials, and in particular relates to a steel for welding wire which adopts composite alloying of multiple alloy elements. Background technique [0002] High-titanium alloy welding wire is the main material for gas shielded welding at present. This type of steel generally requires the control range of Ti to be 0.10%- [0003] Within 0.25%, there are two main problems in this type of steel at present: one is that titanium is easily oxidized during continuous casting of high-titanium alloy wire steel, and TiO 2 1. TiN particles enter the mold slag and cause the performance of the mold slag to deteriorate, resulting in quality problems of continuous casting slabs; 2 Oxidation also exists in the atmosphere. If the amount of alloy is insufficient and the deoxidation is insufficient, pores will be generated in the weld, especially the unevenness of the molten droplets will lead to large fluctuations in ...

AI Technical Summary

Problems solved by technology

[0003]0.25%, there are two main problems in this type of steel at present: one is that titanium is easily oxidized during continuous casting of high-titanium alloy welding wire steel, and TiO is used for nitriding.2, TiN particles enter into the mold slag, causing the performance of the mold slag to deteriorate, resulting in quality problems of continuous casting slabs; second, the alloying elements are also oxidized in the CO2 atmosphere during welding, if Insufficient alloy amount and insufficient deoxidation will lead to pores in the weld, especially the unevenness of the molten droplets will lead to large fluctuations in the welding current and uneven thickness of the molten droplets, which will affect the welding quality. Therefore, the titanium alloy elements in the current high-titanium alloy welding wire steel Generally, it is controlled below 0.12%, which leads to insufficient titanium content in the steel, and the effect of fine grains of titanium, refined weld droplets, and stable welding current during welding is weakened; in the prior art, the titanium content is also controlled at a relatively low High-level technologies mainly focus on full protection casting, optimization of mold flux performance, welding atmosphere control, welding flux control, etc. These technologies can be used as remedial measures after titanium content exceeds the standard; at present, it is necessary to solve the problem of the material itself Starting from the research and development of a new steel type, introducing a variety of elements that have the same or similar effects as Ti elements for composite microalloying, that is, to make use of these microalloying elements to refine the grain, refine the weld droplet, and stabilize the current during welding. , improving the quality of welds, etc., and reducing the titanium content to a certain content range, reducing the oxidation and nitriding of titanium elements in the continuous casting process and welding process of steel caused by high titanium content; the existing technology is aimed at The oxidation of titanium element in the continuous casting process of high-titanium welding wire steel is mainly realized through continuous casting protective casting, but the oxidation and nitriding of titanium in steel cannot be solved by continuous casting protective casting due to the dissolved oxygen and nitrogen in the steel; The problem of oxidation of alloying elements in the welding process is mainly through gas shielded welding, but at present, CO2 atmosphere protection is mostly used, and there are still titanium alloy elements oxidized by CO2 and welding process The problem of secondary nitriding; therefore, at present, it is necessary to start from the high-titanium alloy welding wire material itself and reduce the content of titanium alloy elements through composite micro-alloying, that is, to develop a new material for composite micro-alloying of various alloying elements