冷却速度对铁素体-珠光体带状组织的影响机制  

Mechanism of Effect of Cooling Rate on Ferrite/Pearlite Banded Structure

作　　者：蔡珍[1] 黄运华[1] 张跃[1] 刘静[2] 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]武汉科技大学材料与冶金学院,湖北武汉430000

出　　处：《钢铁研究学报》2012年第6期25-30,共6页Journal of Iron and Steel Research

基　　金：国家自然科学基金资助项目(10876001)

摘　　要：通过建立模型,计算研究了冷却速度对铁素体-珠光体带状组织的影响机制,并通过试验验证了模型计算结果的正确性。结果表明:贫溶质区与富溶质区的Ar3温度差异是产生带状组织的前提条件,碳在贫溶质区产生珠光体之前的扩散距离是带状程度的决定因素。随着冷却速度的增大,贫溶质区与富溶质区的Ar3温度差增大,但碳扩散的距离减小,Ar3温度差对带状组织的影响也减小,带状程度减轻。In order to analyze the mechanism of effect of cooling rate on ferrite/pearlite banded structure, a quantitative model was developed for SAE8822H gear steel. The calculation results are consistent with that of experi- ment obtained by electron microprobe analysis and optical microscopy. The results show that the difference of At3 temperatures for solute-depleted and solute-rich zones in the matrix is a prerequisite for the band formation, while the diffusion distance of carbon prior to pearlite formation in solute-depleted zone is the determinant of the band in- tensity. With the increase of cooling rate, difference between At3 temperatures increases, but the diffusion distance of carbon decreases, meanwhile the influence of difference between Ar3 temperatures on banded structure decreases, then the banded structure relieved.

关 键 词：带状组织 冷却速度 Ar3温度差 碳扩散的距离 

分 类 号：TG142.1[一般工业技术—材料科学与工程]