含V高碳钢的热模拟组织与性能

Microstructure and Properties of V-bearing High Carbon Steel

采用Gleeble-3800热模拟试验机,结合光学显微镜和扫描电镜,研究了含V高碳钢在不同Stelmor控冷条件下的组织与性能。结果显示,对于V含量为0.15%的高碳钢,在650～590℃采用0.55、1 K/s的冷却速度,索氏体化率均能达到97%以上,硬度均在470 HV10以上,但组织中存在少量网状渗碳体;当V含量为0.30%时,在650～590℃采用0.55 K/s的冷却速度,索氏体化率在97%以上,硬度在490 HV10以上,片层间距小于80 nm,网状渗碳体消失。当冷却速度提高到1 K/s时,组织中出现马氏体。

The microstructure and properties of V-bearing high carbon steel under different Stelmor cooling parameters were studied by using Gleeble-3800 thermal-mechanical system combining with OM and SEM. The results show that the sorbite fraction above 0.97 and hardness over 470 HV10 can be obtained for high carbon steel with 0.15%V under the cooling rate of 0.55 K/s or 1K/s during 650 ℃-590℃, but a little cementite network appears. With V content increased to 0.30%, the hardness increases to over 490 HV10 at the same sorbite fraction under the cooling rate of 0.55 K/s during 650℃-590 ℃, pearlite lamellar spacing can be refined to be less than 80 nm, while cementite network disappears. However, martensite appears at the cooling rate of 1K/s.