等温球化退火对某高碳钢中碳化物的影响

Effect of isothermal spheroidizing annealing on carbide in high carbon steel

研究了等温球化退火加热温度对高碳钢碳化物球化质量的影响。采用扫描电镜(SEM)和图像软件等技术手段分析碳化物的数量、尺寸和形貌,表征试验钢的球化质量。结果表明,加热温度由750℃升高至790℃,锻态组织中片层状珠光体都基本实现了球化。随着加热温度的升高,奥氏体逐渐均匀化,析出片状碳化物几率升高,影响球化质量。770℃加热时碳化物数量最多,平均粒径、圆度、粒径均方差最小,尺寸均匀性最好。

The influence of heating temperature of isothermal spheroidizing annealing on the carbide spheroidization quality of high carbon steel was investigated. The scanning electron microscopy（ SEM）,image software and other technical methods were applied to analyze the number,size and morphology of the carbides. The results show that the heating temperature from 750 ℃ to 790 ℃,the lamellar pearlite in the forging state was basically spheroidized. With increasing heating temperature,the composition of austenite was gradually homogenized,the precipited lamellar carbides were easy to form,which affects spheroidization quantity of carbides. After heating at 770 ℃ for the isothermal spheroidizing annealing,the number of carbide is the largest,and the average particle size,the roundness and the standard deviation of carbide distribution are the smallest and size uniformity is the best.