Method for smelting high-nitrogen austentite stainless steel through pressurized electroslag remelting gas nitriding

Abstract

The invention belongs to the technical field of high-nitrogen steel smelting, and particularly relates to a method for smelting high-nitrogen austentite stainless steel through pressurized electroslag remelting gas nitriding. The method is characterized in that a consumable electrode base material with the nitrogen content being (0.75-0.9)x[%N] is smelted in a smelting furnace according to target steel grade ingredients, and the consumable electrode base material is forged into a consumable electrode; arcing slagging is conducted through a solid-state arcing method under protection of nitrogen; and nitrogen is led into a smelting chamber to increase the pressure to 1 MPa to 3 MPa, the cooling water pressure is synchronously increased, and smelting and feeding forming are conducted at a low smelting speed under the voltage ranging from 40 V to 45 V and the current ranging from 3000 A to 4200 A. The method has the beneficial effects that alloying of nitrogen in the high-nitrogen austentite stainless steel is efficiently conducted through the gas nitriding method by reasonably controlling the current, the voltage, the nitrogen pressure and other parameters, and the technical support is provided for development of the high-nitrogen austentite stainless steel high in nitrogen content, uniform in ingredient and excellent in performance.

Description

technical field [0001] The invention relates to the field of high-nitrogen steel smelting, in particular to a method for smelting high-nitrogen austenitic stainless steel by pressurized electroslag remelting gas-phase nitriding. Background technique [0002] Because austenitic stainless steel has good toughness, resistance to uniform corrosion and local corrosion, it is widely used in chemical industry, paper and pulp industry, medical equipment, etc., but the insufficient strength of low carbon and ultra-low carbon austenitic stainless steel limits this. Further application of class steel. Nitrogen is added to austenitic stainless steel as a gap strengthening element, which can greatly improve the stability of austenite, partially or completely replace expensive Ni, and improve the strength of steel through the synergistic effect with other alloying elements (Cr, Mo, etc.) , toughness, wear resistance and corrosion resistance, etc. [0003] Under normal pressure, in order...

AI Technical Summary

Problems solved by technology

However, the smelting parameters and nitrogen pressure of the pressurized electroslag remelting process have a significant impact on the nitrogen content in high-nitrogen austenitic stainless steel and the quality control of the ingot. If the process is not properly matched, the nitrogen increase effect will be significantly reduced, and even slag grooves will be generated. surface quality problem

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