Cast-rolling method for suppressing central segregation of chromium and molybdenum elements in super austenitic stainless steel

Abstract

The invention discloses a cast-rolling method for restraining a Cr element and a Mo element of super-austenitic stainless steel from center segregation and belongs to the technical field of manufacturing of the super-austenitic stainless steel. The method includes the steps that (1) raw materials are weighed according to the composition proportion of the super-austenitic stainless steel, and the raw materials are subjected to heat preservation at the temperature ranging from 150 DEG C to 250 DEG C for 100 minutes to 150 minutes; (2) the raw materials are sorted and placed into a vacuum induction melting furnace step by step to obtain molten steel by being smelted; and (3) the molten steel is poured into a dual-roll thin strip cast-rolling machine for cast rolling under shielding of high-purity nitrogen, and a thin super-austenitic stainless steel strip 2.0-3.0 mm thick is obtained, wherein the pouring temperature ranges from 1450 DEG C to 1550 DEG C, the cast-rolling speed ranges from 10 m / min to 40 m / min, and the cast-rolling force ranges from 30 kN to 70 kN. According to the manufactured thin super-austenitic stainless steel strip, center segregation of the Cr element and the Mo element is restrained, and on the premise of maintaining the plasticity, the yield strength is improved by 5%-10% compared with that of traditional strip steel of the same specification as the thin super-austenitic stainless steel strip. Meanwhile, the cast-rolling method reduces energy consumption and production cost, improves the utilization rate of materials and reduces environmental pollution.

Description

technical field [0001] The invention belongs to the technical field of super austenitic stainless steel preparation, and in particular relates to a casting and rolling method for suppressing central segregation of chromium and molybdenum elements in super austenitic stainless steel. Background technique [0002] Super austenitic stainless steel is a kind of high-alloyed stainless steel. Its thin-gauge cold-rolled sheet has a wide range of applications in harsh environments such as chemistry, pharmaceuticals, petrochemicals, and power plants. Compared with ordinary austenitic stainless steel, super austenitic stainless steel contains a large amount of alloying elements such as Cr, Ni, Mo, etc., which makes it have higher strength, toughness and plasticity, and excellent welding performance. The substantial improvement of corrosion resistance in this medium meets the needs of users for materials that can resist harsh environments, making the application range and demand for su...

AI Technical Summary

Problems solved by technology

Aiming at the serious segregation of Cr and Mo elements and the precipitation of a large number of second phases in super austenitic stainless steel, there is no efficient solution at present. The main technical means for industrial production are: increasing the solution treatment temperature and increasing the solution treatment time. The solution treatment temperature is as high as 1200°C or even higher. The solution treatment temperature is much higher than that of ordinary austenitic stainless steel. Therefore, higher requirements are placed on the capacity of the heating furnace equipment, and the material Burning loss and energy consumption reduce the utilization rate of materials and increase the bearing capacity of the environment, which is not conducive to the sustainable green development of economy and environment

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