Steel for composite microalloying 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] 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 the welding current and uneven thickness of the molten droplets, which will affect the welding quality. Therefore, the current high titanium Titanium alloy elements in alloy welding wire steel are generally controlled below 0.12%, which leads to insufficient titanium element content in the steel, and weakens the effects of fine grains of titanium elements, refined weld droplets, and stable welding current during welding and use; There are also technologies to control the titanium content at a relatively high level, mainly focusing on full protection casting, optimizing the performance of mold slag, controlling the welding atmosphere, and controlling the welding slag. This technology can be used as a remedial measure after the titanium content exceeds the standard; at present , it is necessary to start from the problems of the material itself, research and develop a new steel type, and introduce a variety of elements that play the same or similar roles as Ti elements for composite microalloying, that is, to make use of these microalloying elements during welding. Thinning the weld droplet, stabilizing the current, improving the quality of the weld, etc., and reducing the titanium content to a certain content range, reducing the continuous casting process of steel caused by high titanium content and controlling the oxidation and nitrogen of titanium elements during the welding process. The prior art controls the oxidation of titanium elements in the continuous casting process of high-titanium welding wire steel mainly through continuous casting protection casting, but the dissolved oxygen and nitrogen in the steel cannot solve the oxidation and nitriding of titanium in the steel. Continuous casting and protective casting solve the problem of controlling the oxidation of alloy elements in the welding process, mainly through gas shielded welding, but currently CO 2 Atmosphere protection, there are still titanium alloy elements being destroyed by CO 2 Oxidation and secondary nitriding in the welding process; therefore, at present, it is necessary to start from the high-titanium alloy welding wire itself and reduce the content of titanium alloy elements through composite micro-alloying, that is, to develop a new composite micro-alloying of various alloying elements. Material