20Cr2Ni4 gear steel and production technology thereof

Abstract

The invention discloses 20Cr2Ni4 gear steel and a production technology thereof. The 20Cr2Ni4 gear steel is made of 20Cr2Ni4, and the mass percentage of Mo in the 20Cr2Ni4 is 0.15-0.30%. The production technology comprises the steps of burdening, smelting in an electric arc furnace and smelting in a refining furnace, wherein in the smelting process in the electric arc furnace, steel is molten, the temperature reaches 1570-1590 DEG C, and sampling is carried out for detection analysis so as to enable the mass percentage of the Mo to reach 0.15-0.30%; and in the smelting process in the refining furnace, the temperature reaches 1570-1590 DEG C, and sampling is carried out for detection analysis so as to enable the mass percentage of the Mo to reach 0.15-0.30%. According to the 20Cr2Ni4 gear steel and the production technology thereof, impurities in the steel are reduced, the content of H, O and N gas in the steel is reduced, the harmful elements such as P, S, As and Sn in the steel are reduced, a proper amount of the Mo is added, and therefore the steel can be used for parts such as a large gear and a shaft, and the comprehensive performance such as the hardenability, the heat resistance, the grain refinement performance and the steel strength improvement performance can be improved.

Description

technical field [0001] The invention relates to the technical field of steel materials, in particular to a 20Cr2Ni4 gear steel and a production process thereof. Background technique [0002] 20Cr2Ni4 is a high-strength alloy carburizing steel with good comprehensive mechanical properties, and its hardenability, strength and toughness are all higher than 12CrNi3 steel. The forging performance of this steel is good, the forging heating temperature is 1200°C, the initial forging temperature is 1150°C, the final forging temperature is greater than 850°C, and it is cooled slowly after forging. If 20Cr2Ni4 steel has coarse grains after forging, even after normalizing and subsequent carburizing heating, coarse martensite structure will still be obtained after quenching. It is used for large cross-section carburized parts, such as large gears, shafts, and quenched and tempered parts that require high strength and good toughness. The chemical composition of the steel: C0.17-0.23%, ...

AI Technical Summary

Problems solved by technology

The chemical composition of the steel: C0.17-0.23%, Si0.17-0.37%, Mn0.30-0.60%, Cr1.25-1.65%, Ni3.25-3.65%, Mo≤0.10%. With the continuous upgrading of product quality and requirements, according to the control of elements within the original chemical composition range, the properties such as hardenability, heat strength, grain size, and strength cannot meet customer requirements.