低碳低合金铸钢在正火过程中的组织演变  

Microstructure Evolution of Low Carbon Low Alloy Steel During Normalizing

作　　者：赵小朋[1] 安立聪 李宏涛[1] 杨弋涛[1] 

机构地区：[1]上海大学材料科学与工程学院,上海200072

出　　处：《铸造技术》2014年第3期488-490,共3页Foundry Technology

基　　金：教育部"卓越工程师"培养项目;国家级大学生创新创业训练计划项目

摘　　要：通过观察试样保温不同时间后立即快速淬火后的金相组织，测定布氏硬度及不同组织的显微硬度，研究了一种低碳低合金铸钢在970℃正火时的组织演变规律。结果表明，低碳低合金铸钢试样在970℃保温2min淬火开始生成板条马氏体，保温2～10min时得到铁索体、珠光体和马氏体3种组织；随保温时间延长，铁素体含量降低；保温时间大于10min后，得到的组织均为板条马氏体。保温25min和40min时，试样表面硬度低于心部，初步分析认为是表面氧化脱碳和晶粒粗化所致。Microstructure evolution of a low carbon and low alloy cast steel in normalizing process was investigated by observing the microstructure and testing the Vickers hardness of samples normalized at 970℃ for different holding times. The results show that lath martensite is got in the samples heated for 2 min; ferrite, perlite and martensite are got in the samples heated for 2-10 rain; the content of ferrite decreases with the increase of holding time; only lath martensite appear in the microstructure when the holding time is longer than 10 min. After the holding time for 25 and 40 min, the surface hardness is lower than core hardness for surface oxidation and grain coursing.

关 键 词：低碳低合金铸钢 组织演变 正火 

分 类 号：TG156.4[金属学及工艺—热处理]