2 results about "Chromium nickel" patented technology

The application discloses a production method of medium-high-chromium nickel-reduced austenitic stainless steel strip, which comprises the steps of continuous casting, heating in a heating furnace, rough rolling, finish rolling and the like, wherein the process parameters of the continuous casting step are adjusted to lay a foundation for rough rolling, and the temperature settings of each stage in the heating furnace ensure that the temperature inside and outside the slab is uniform; and because the heating speed is moderate, the slab will not be cracked due to excessive local thermal stress; the target temperature T in the second heating section is calculated according to a formula according to the actual composition; the setting of the target temperature can ensure that the continuous casting blank is heated away from the high-temperature two-phase zone temperature, and the growth of ferrite in high-temperature production is avoided, thereby reducing the risk of edge cracking and ensuring that the high-nitrogen continuous casting blank obtains the necessary heating temperature, and the phenomenon of being unable to be rolled in the rolling process is avoided. Through the whole-process process adjustment and optimization, the medium-high-chromium nickel-reduced austenitic stainless steel coil obtained is free of edge cracking, has good surface quality, and only has sporadic peeling defects or no peeling defects.

This application belongs to the field of metallurgical technology, and particularly relates to a smelting method for improving the purity of high-temperature alloys. Because chromium has a strong affinity for oxygen when the chromium content in high-chromium nickel-based high-temperature alloys is high, if titanium is directly added for alloying, titanium will preferentially react with residual oxygen and nitrogen to form TiO2 and TiN inclusions, resulting in extremely low titanium yield and deterioration of purity. The embodiments of this application break through the limitations of traditional single deoxidation modes. Based on the thermodynamic coupling reaction characteristics of oxygen, nitrogen, and titanium in the high-temperature alloy smelting process, a multi-stage thermodynamic deoxidation technology route with synergistic matching of temperature, deoxidizer type, and deoxidation depth is constructed. Through a sequential combination of carbon pre-deoxidation – strong deoxidizing metal + rare earth enhanced deoxidation – low-temperature titanium alloying, a controllable metallurgical transformation from high-oxygen-content raw materials to ultra-pure high-titanium melt is achieved. This solves the technical contradiction of difficulty in simultaneously achieving purity and precise composition control in high-chromium, high-titanium nickel-based high-temperature alloys due to the high activity of titanium and the difficulty in controlling oxygen and nitrogen.