Q345B和AH32连铸板坯不同部位的高温延塑性  

High temperature ductility of Q345B and AH32 continuous casting slabs at different positions

作　　者：曾强国[1,2] 张博[1] 王福明[1] 

机构地区：[1]北京科技大学冶金与生态工程学院,北京100083 [2]安阳钢铁集团有限责任公司,安阳455004

出　　处：《北京科技大学学报》2014年第2期183-188,共6页Journal of University of Science and Technology Beijing

摘　　要：通过Gleeble--1500热模拟试验机,分别对取自同一块Q345B钢板坯的横向、纵向、竖向和中心四个方位的试样和AH32钢板坯表面及其厚度1/4处的六组不同部位的纵向试样进行了高温延塑性的研究.采用了金相显微镜和扫描电镜方法对断口和附近的组织进行了观察.研究结果发现:Q345B钢板坯四个方位的试样低温区域(950℃以下)高温延塑性曲线变化较小,而高温区域(950℃以上)的延塑性曲线变化相对较大.AH32钢板坯表面的三组纵向试样的高温延塑性曲线变化规律相同,断面收缩率没有出现特别大的波动;而厚度1/4处的三组试样的高温延塑性曲线与表面的三组试样差异较大,断面收缩率发生了很大波动,其原因主要是试样位于发达的柱状晶区,较表面的等轴晶区更容易出现微裂纹、元素的偏析、铸坯组织疏松等缺陷.The high temperature ductility of samples, taking from a Q345B continuous casting slab in the transverse direction, drawing direction, vertical direction and at the central part, as well as an AH32 continuous casting slab at the surface and 1/4 thick-ness position, was investigated by using a Gleeble-1500 testing machine. The fractographs and microstructures of high-temperature tensile samples were observed by optical microscopy and scanning electron microscopy. Experimental results show that the high temper-ature ductility below 950℃ changes little between 4 groups of different samples from the Q345B slab, but the variation tendencies of high temperature ductility above 950℃ are greatly different. The changes of high temperature ductility of 3 groups of samples from the AH32 slab at the surface are the same, and the reduction of area has little fluctuation. Whereas the high temperature ductility of 3 groups of samples at the 1/4 thickness differs entirely from that at the surface, and the reduction of area appears fluctuant greatly. The reason is that microcracks, composition segregation, porosity and looseness occur more easily in the columnar crystal zone of sampling than in the equiaxed crystal zone of the surface.

关 键 词：低合金高强钢 连铸板坯 高温性能 延展性 

分 类 号：TF777.1[冶金工程—钢铁冶金]