新型高强韧性弹簧钢40T 和44T 脱碳倾向的研究

新型高强韧性弹簧钢40T(%:0.41C-2. 12Si- 1.03Cr- 1.98Ni-0.31Mo-0.25V),44T(%:0.44C-2.28Si- 1.42Cr-0.25V)和弹簧钢60Si2CrVA(%:0.59C-1.65Si-1.11Cr-0.18V)的φ18 mm 和φ26 mm 试验钢材由北满特钢 20t电弧炉冶炼，经轧制、冷拔而成。各钢材经860～1000℃加热脱碳试验的结果表明，40T钢碳含量较低，并 有～2%Ni,其脱碳倾向明显低于44T钢和60Si2CrVA钢；880 ℃加热1 h时，40T钢没有脱碳，44T钢脱碳层深 0.05mm,60Si2CrVA钢脱碳层深0.15 mm;1000 ℃加热20 min,40T钢脱碳层深0.1 mm,44T 钢0.2 mm, 60Si2CrVA钢0.4 mm。40T钢脱碳倾向小，有利于提高弹簧的疲劳寿命。

A Study on Decarburization Trend of New High Strength and Toughness Spring Steels 40T and 44T

The φ18mm and φ26mm test stel products of new high strength and toughness spring steel 40T;0.41C- 2.12Si- 1.03Cr- 1.98Ni-0.31Mo-0.25V,steel 44T:0.44C-2.28Si- 1.42Cr-0.25V and spring steel 60Si2CrVA:0.59C- 1.65Si- 1. 11Cr-0. 18V were produced by 20 t are fumace melting, rolling and cold drawing. The results of each steel product by heating decarburizing test showed that due to lower carbon content and contained ～2% Ni in steel 40T, the decarburization trend of steel 40T obviously lower that of steel 44T and steel 60Si2CrVA: heating at 880 ℃ for 1h, there was nodecarburization in steel 40T, depth of decarburization layer was 0.05mm in steel 44T and 0.15 mm in steel 60Si2CrVA; and heating at 1000 ℃ for 20 min, the depth of decarburization layer was 0. 1mm in steel 40T, 0.2 mm in steel 44T and 0.4 mm in 60Si2CrVA. The smaller decarburization trend of steel 40T is favourable to increase the fatigue life of spring.