High-strength rare earth ytterbium heat-resistant steel and manufacture method thereof

Abstract

The invention relates to high-strength rare earth ytterbium heat-resistant steel and a manufacture method thereof. The heat-resistant steel comprises the following chemical components by mass percentage: 0.05-0.12% of C, 0.2-1.5% of Si, 0.5-1.7% of Mn, less than or equal to 0.045% of P, less than or equal to 0.030% of S, 24.0-26.0% of Cr, 19.0-22.0% of Ni, 0.03-0.6% of Yb, and the balance of Fe and the unavoidable impurity element; and the following condition should be simultaneously satisfied: Creq / Nieq is less than or equal to 1.165, Creq is Cr+1.5Si, and Nieq is Ni+30C+0.5Mn. By adding rare earth ytterbium, crystal boundary intensity is increased, the method provides favorable condition for increasing carbon content in the heat resistant steel, so that the high temperature intensity and service life of the steel are increased, the reasonable manufacturing process condition is cooperated, under guarantee of mechanical properties, the grain size of the heat-resistant steel can reach 4-6 grade, and the steel antioxidation performance is increased.

Description

technical field [0001] The invention relates to the field of heat-resistant steel for high temperature, in particular to a high-strength rare earth ytterbium heat-resistant steel and a manufacturing method thereof. Background technique [0002] 310S heat-resistant steel is a heat-resistant steel that has been used in high-temperature fields for a long time. Its high-chromium and high-nickel alloy composition makes it have better high-temperature heat resistance. However, due to long-term use under high temperature conditions, the carbon content in the steel aggregates at high temperatures, causing microscopic holes in the steel material, causing internal defects in the material structure, resulting in a decrease in material strength and failure. Reducing the carbon content in steel plays a certain role in the high-temperature accumulation of carbon, which can prolong the high-temperature service life of 310S heat-resistant steel. However, the high-temperature strength of 31...

AI Technical Summary

Problems solved by technology

However, the high-temperature strength of 310S heat-resistant steel is mainly guaranteed by the carbon content, and reducing the carbon content will inevitably reduce the high-temperature strength of the heat-resistant steel

Therefore, at present, we have to comprehensively consider the high temperature strength and service life, and control the carbon content of 310S heat-resistant steel according to the middle and lower limits

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