关键词: 弹簧钢, 室温蠕变, 临界蠕变应力, 回复

Abstract: Test results showed that the creeps of spring of steel 44Si2CrV quenched + medium tempering and removed decarburized layer happened at room temperature as stress was higher than critical creep stress value, and the higher tensile or shear strength, the higher critical creep stress. The critical creep stress τ_cc of steel 44Si2CrV quenched at 900 P and tempered at 500°C was 700 MPa, τ_cc  quenched at 900°C and tempered at 380 °C was 800 MPa. The plastic deformation speed was higher at creep beginning, then decreased abruptly. The creep stopped at certain stress for definite time. After loading for a long time and creep of spring stopped, as the spring was heated at 200 °C for 2 h air cooled, the free height of spring increased, and the creep of spring restarted again when it is loaded with original stress.