Martensite heat-resistant steel and grain display method thereof

Abstract

The invention relates to martensite heat-resistant steel and a grain display method thereof and belongs to the field of metal material micro-technology. The steel comprises the chemical components, by weight, of 0.05%-0.15% of C, 0.7% or the less of Si, 0.8% or the less of Mn, 0.020% or the less of P, 0.020% or the less of S, 13.0%-15.0% of Cr, 4.0%-4.5% of Ni, 2.0%-2.5% of Mo, 3.0%-4.0% of W, 0.15%-0.35% of Nb, 0.30%-0.35% of N and the balance Fe and inevitable impurities. A cylindrical specimen with phi being 15 mm x15 mm is cut on a quenched workpiece. The specimen is put into a heat treating furnace at the temperature of 700-720 DEG C to be heated for 30-40 minutes, and then put into water to be cooled. A grain size specimen is polished on metallographical sand paper with the meshes being 200, 500, 800 and 1000 separately and buffed on a metallographical buffing machine. The surface of the specimen is observed, after the surface of the specimen is free from scratches visible to naked eyes and defects, corrosion is conducted. The martensite heat-resistant steel and the grain display method thereof have the advantages that the problem that when the grain size of the martensite heat-resistant steel is detected, grain boundaries do not occur can be solved, corrosion liquid does not needed to be heated at the time of corrosion, the operation is easy and the method is easy to master.

Description

technical field [0001] The invention belongs to the field of metal material microtechnology, and in particular relates to a martensitic heat-strength steel and a grain display method thereof, which are mainly applicable to the fields of metallurgy, machinery, energy, aviation, aerospace, chemical industry and the like. Background technique [0002] Martensitic heat-strength steel is an important type of heat-resistant steel, and heat-resistant steel is an important type of heat-resistant steel. Heat-resistant steel can be divided into heat-strength steel, valve steel and oxidation-resistant steel (also known as anti-oxidation and non-skinning steel) according to performance and use. Valve steel is also called valve steel, which mainly refers to the steel used to manufacture the intake and exhaust valves of internal combustion engines. Such steels are required to have good high-temperature strength, high-temperature hardness, creep resistance and flue gas corrosion resistanc...

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Problems solved by technology

[0005] The object of the present invention is to provide a martensitic heat-strength steel and a method for displaying its grain size. This method can solve the problem that the grain boundary does not appear when detecting the grain size of the martensitic heat-strength steel, and has the advantage of not needing heating during corrosion. Corrosive solution, this method has the characteristics of simple operation and easy mastery

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