Q345c连铸坯在热装热送中表面裂纹成因分析  

Surface cracks analysis on continuous casting slab Q345c during hot delivery and hot charging

作　　者：王生朝[1,2] 赵刚[1] 鲍思前[1] 

机构地区：[1]武汉科技大学材料与冶金学院,湖北武汉430081 [2]湖南工业大学冶金工程学院,湖南株洲412007

出　　处：《中南大学学报（自然科学版）》2013年第9期3634-3639,共6页Journal of Central South University:Science and Technology

基　　金：湖南省科学技术厅科技计划项目(2011GK3147)

摘　　要：应用有限元软件(ABAQUS)对Q345c连铸板坯单坯冷却过程温度场和应力场进行模拟,通过Gleeble 2000热模拟试验机研究Q345c钢连铸坯的高温热塑性,测得材料的高温热塑性曲线和高温抗拉极限曲线。研究结果表明:材料的脆性区在600~850℃之间,高温断裂强度随温度升高而降低,最大不超过160 MPa;板坯单独冷却在850~750℃之间,正处在材料的脆性区,模拟所得其表面拉应力,最大达到164 MPa,超过材料的高温抗拉强度;为避免过高的表面热应力产生热裂纹缺陷,连铸火焰切机至板坯加热炉之间,除应安装保温加热装置外,尽量缩短板坯的输送时间,必要时堆垛缓冷。The temperature field and stress field were simulated using the finite element software(ABAQUS) for Q345c continuous casting slab during cooling process.The hot ductility of continuous casting Q345c slabs was tested by Gleeble 2000 thermal/strain simulation machine.The hot ductility curve and high temperature tensile strength curve were obtained according to thermal simulation experiments.The results show that the temperature of brittleness zone is in 600 850 ℃,high temperature tensile strength decreases with increasing temperature and the maximum does not exceed 160 MPa.The simulation value of surface stress is up to 164 MPa and larger than the high temperature tensile strength in the cooling process of the single slab.At the same time temperature between 750 850 ℃ is in the brittle zone of the material.In order to avoid hot crack defects caused by excessive thermal stress on the surface in the process of hot slab delivery,the insulation heating device should be installed between the flame cutting machine and the heating furnace,and the delivery time of slab should be shorter.Furthermore,if necessary,slabs need to be stacked up to slow down the cooling speed.

关 键 词：连铸坯 温度场 应力分析 导热系数 裂纹 高温热塑性 

分 类 号：TF777[冶金工程—钢铁冶金]