Effect of Welding Process on Microstructure and Properties of High Strength Steel Joints

2018 3rd International Conference on Insulating Materials, Material Application and Electrical Engineering

材料科学;无线电电子学;电工学

Zong, Xuemei^1,2 ; Ma, Guo^1 ; Yang, Chao^3 ; Wang, Can^1,2 ; Zhang, Liping^1,2

Jiangsu Xugong Engineering Machinery Research Institute Co. Ltd., Jiangsu, Xuzhou

221004, China^1

State Key Laboratory of Intelligent Manufacturing of Advanced Construction Machinery, Jiangsu, Xuzhou

221004, China^2

Xuzhou XCMG Schwing Machinery Co. Ltd., Jiangsu, Xuzhou

221004, China^3

关键词: Construction machinery;    Cooling rates;    Impact absorption;    Microstructure and properties;    Preheating temperature;    Research object;    Welding heat input;    Welding process;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/452/2/022143/pdf
DOI  :  10.1088/1757-899X/452/2/022143

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

S900MC high strength steel was selected as the research object, and different MAG welding processes were designed according to the practical application of construction machinery. The microstructure, tensile test and impact test of the welded joints were carried out under different conditions. The effects of welding heat input, preheating temperature and cooling time t8/5 on the tensile strength and impact toughness of welded joints were studied. The results show that the microstructure of the welded joint is composed of weld, fusion zone, superheated zone, fine grain zone and incomplete recrystallization zone. When the welding line energy or preheating temperature is increased, the cooling rate decreases, the strength of the welded joint decreases. The impact absorption energy of the weld is about 50% higher than that of HAZ. With the increase of t8/5, the impact absorption energy of the weld and HAZ increases first and then decreases. When t8/5 is 15-20s, the impact absorption energy is the largest.