Study On Welding Of Q345B Steel Based On Multi-strand Twisted Welding Wire

This paper is based on the invention patent of a multi-strand twisted welding wire,with multi-strand twisted welding wire as the research object,and the practical performance of multi-strand twisted welding wire is studied through the welding of Q345 B low alloy steel.In view of the welding of Q345 B low-alloy high-strength steel,the welding property is theoretically calculated,and the sensitivity index of welding cold crack is0.20%,indicating that the steel welding is not required to be preheated.he welding property is theoretically calculated and does not need preheating in welding.ANSYS software is used to simulate the welding numerical simulation of Q345 B low alloy steel open V groove butt butt welding experiment with different welding line energy source.Analysis the effect of different preheating temperature on the distribution of temperature field and stress field,and peculated that the appropriate welding line energy value,it is concluded that the welding line energy used for welding Q345 B low alloy steel is 700J/mm,and the welding parameters of welding Q345 B steel with multiple stranded wire are determined.It provides the guiding significance for the use of multi-strand twisted welding wire to weld low alloy steel.According to the welding requirements of Q345 B low alloy steel,by analyzing the effect of the alloy element on the weld structure transformation,it is determined that the alloy composition of the multi-strand twisted welding wire alloy is suitable for the welding of Q345 B steel plate.According to the existing different types of wire,two kinds of different stranded wire A and multi-strand twisted welding wire B are made by the rational design of the various strand wires,and used for Q345 B steel plate welding,and provide theoretical reference for the study of multiple stranded wire.Using MAG,the multi-strand twisted welding wire A,multi-strand twisted welding wire B and ER49-1 welding wire are used to weld the Q345 B steel respectively under the welding line energy of 700J/mm.The influence of the type of welding consumables on the microstructure and properties of the welded joints,and the experimental results as follows: the average tensile strengths of the multi-strand twisted welding wire A,multi-strand twisted welding wire B and ER49-1 welding wire are 525 Mpa,534Mpa and 517 Mpa,and the average yield strength values are383 Mpa,395Mpa and 377Mpa;The average impact energy values of the weld metalweld zone are 92 J,103J and 96.7J,the average impact energy values in the weld heat affected zone are 131 J,142J and 135.7J,the average Rockwell hardness value in the weld zone are 54.4HRA,54.3HRA and 56.0HRA.The average Rockwell hardness values in the HAZ were 55.9 HRA,54.9 HRA,and 56.4 HRA.and the results shows that the multi-stranded twisted welding wire A and the multi-stranded twisted welding wire B can be applied to the Q345 B steel welding,and the welded joint has a good overall performance,especially the use of multiple stranded wires B has the best overall performance of the welded joints;it provides a theoretical basis for the application of multiple stranded wires in low alloy steel welding.