GCr15轴承钢软化退火工艺

Softening annealing process of GCr15 bearing steel

在温度为550~900℃时,对GCr15轴承钢进行退火,观察其显微组织变化,并进行硬度测试,对退火及脱碳转变机理进行分析与讨论。结果表明:在550℃退火时,GCr15轴承钢的组织和热轧状态基本没有变化;在600~750℃退火时,随着温度的升高,细片状珠光体的片层间距逐渐增大,到750℃时细片状珠光体基本消失,主要为球化碳化物颗粒和长条状碳化物颗粒;在760~800℃退火时,随着温度的升高,组织逐渐趋向完全球化;在850~900℃退火时,随着温度的升高,粗片状珠光体逐渐增加;在550~900℃退火时,其硬度呈先下降后上升的趋势;在750~900℃退火时,硬度均小于245 HBW,满足标准要求。

The GCr15 bearing steel was annealed at 550-900 ℃, and its microstructure was observed.The hardness was tested, and the annealing and decarburization transformation mechanisms were analyzed and discussed. The results show that the microstructure and hot rolling state of GCr15 bearing steel annealed at 550 ℃ had not changed basically. When annealed at 600-750 ℃, with the increase of temperature, the lamellar spacing of fine lamellar pearlite gradually increased, and the fine lamellar pearlite basically disappeared at 750 ℃, which was mainly composed of spheroidized carbide particles and strip carbide particles. When annealed at 760-800 ℃, the microstructure gradually tended to complete globalization with the increase of temperature. When annealed at 850-900 ℃, the coarse lamellar pearlite gradually increased with the increase of temperature. When annealed at 550-900 ℃, the hardness first decreased and then increased. When annealed at 750-900 ℃, the hardness was less than 245 HBW, which met the standard requirements.