喷射成形H13钢的高温热变形及组织演变  

High-temperature Thermal Deformation and Microstructure Evolution of Spray Formed H13 Tool Steel

作　　者：张金祥[1] 黄进峰[1] 崔华[2] 张济山[1] 

机构地区：[1]北京科技大学新金属材料国家重点实验室,北京100083 [2]北京科技大学材料科学与工程学院,北京100083

出　　处：《热加工工艺》2014年第20期1-5,共5页Hot Working Technology

基　　金：国家重点基础研究发展计划(973)项目(2011CB606303)

摘　　要：采用等温热压缩方法研究了在变形温度为850～1150℃，变形速率为0．1～10s-1，最大真应变为0．7时，热变形参数对铸造与喷射成形H13钢流变应力和显微组织的影响。结果表明，两者在变形过程中均表现出动态再结晶特征，变形温度和应变速率对合金流变应力的影响显著．流变应力随变形温度的降低和应变速率的增加而增大。喷射成形H13钢由于晶粒细小，组织均匀，无宏观偏析，促进了再结晶的进行，有利于热变形加工。并且热变形后孔隙得到闭合，致密度提高。铸造H13钢变形后的组织带状偏析明显，退火后依然存在碳化物偏析带，而喷射成形H13钢无论是变形后组织还是退火组织，都很均匀。没有宏观偏析。The hot compression deformation behavior of cast and spray-formed H13 steel was investigated on Gleeble-1500 hot simulator at 850-1150℃, strain rate of 0.1-10 s-1and maximum true strain of 0.7. The results show that both the cast and spray-formed H13 steel can exhibit dynamic recrystallization in the deformation process. Both the deformation temperature and strain rate have obvious influences on the flow stress, which increases gradually with decreasing temperature and increasing strain rate. As a result of the much finer and more homogeneous grain structures of spray-formed H13 steel, the recrystallization behavior is promoted, which is beneficial to the thermal deformation processing. Moreover, after hot deformation, the pores get closed and the density is greatly improved. The band segregation can hardly be seen in the spray-formed H13 steel, which is obvious in the cast H13 steel both in the deformed and deformed-annealed states.

关 键 词：喷射成形 H13钢 热变形 组织 

分 类 号：TG142.1[一般工业技术—材料科学与工程]