Effect of Mg Addition on Inhibiting Austenite Grain Growth in Heat Affected Zones of Ti-Bearing Low Carbon Steels  

作　　者：ZHU Kai YANG Jian WANG Rui-zhi YANG Zhen-guo 

机构地区：[1]Department of Materials Science, Fudan University, Shanghai 200433, China [2]Metallurgical ProcessDepartment, Research and Development Center, Baoshan Iron and Steel Co Ltd, Shanghai 201900, China

出　　处：《Journal of Iron and Steel Research International》2011年第9期60-64,共5页

摘　　要：To study the effect of Mg addition on inhibiting weld heat affected zones （HAZ） austenite grain growth of Ti-bearing low carbon steels, two steels with and without Mg treated were prepared using a laboratory vacuum. The welding testing was simulated by Gleeble 3500 thermomechanical simulator. The performance of HAZ was investiga ted that the toughness was improved from 3.3 to 185 J by adding 0. 005%Mg （in mass percent） to the steel, and the fracture mechanism changed from cleavage fracture to toughness fracture. Through in-situ observation by a confocal scanning laser microscope, a significant result was found that the austenite grain of the steel with Mg treated was still keeping fine-grained structure after holding at 1 400℃ and lasting for 300 s. This inhibition of austenite grain growth was mainly attributed to the formation of pinning particles after the addition of Mg. The obtained results pro pose a potential method for improving HAZ toughness of structure steels.To study the effect of Mg addition on inhibiting weld heat affected zones （HAZ） austenite grain growth of Ti-bearing low carbon steels, two steels with and without Mg treated were prepared using a laboratory vacuum. The welding testing was simulated by Gleeble 3500 thermomechanical simulator. The performance of HAZ was investiga ted that the toughness was improved from 3.3 to 185 J by adding 0. 005%Mg （in mass percent） to the steel, and the fracture mechanism changed from cleavage fracture to toughness fracture. Through in-situ observation by a confocal scanning laser microscope, a significant result was found that the austenite grain of the steel with Mg treated was still keeping fine-grained structure after holding at 1 400℃ and lasting for 300 s. This inhibition of austenite grain growth was mainly attributed to the formation of pinning particles after the addition of Mg. The obtained results pro pose a potential method for improving HAZ toughness of structure steels.

关 键 词：low carbon steel Mg microstructure pinning mechanism 

分 类 号：TG142.33[一般工业技术—材料科学与工程] TG457.11[金属学及工艺—金属材料]