Q345B钢结构厂房焊接工艺研究

根据福建某企业Q345B钢结构厂房建设实际,分别使用CO2气体保护焊和焊条电弧焊两种焊接方法对厚度20 mm的Q345B钢板进行焊接,对焊接接头进行外观及无损探伤检测,并系统研究焊接试样的力学性能和组织结构。结果表明：焊条电弧焊和CO2气体保护焊工艺均能够用于Q345B钢结构厂房的焊接,焊接质量均能达到国家标准,但CO2气体保护焊接头的抗拉强度和伸长率均高于焊条电弧焊接头,且显微硬度分布更均匀;焊接方法对焊接接头各区域的组织构成影响不大,但焊条电弧焊接头各区域的晶粒尺寸均大于CO2气体保护焊接头;采用16 KJ·cm^-1热输入的CO2气体保护焊接头具有最优的综合力学性能,且焊缝组织最为均匀,推荐企业优先选用此种焊接工艺。

A Study of Welding Procedure of Q345B Steel for Steel Structure Workshop

According to the actual construction of the Q345 B steel structure workshop in a fujian enterprise,CO2 gas shielded welding and welding rod arc welding,the two methods were used for the 20 mm thickness of Q345 B steel welding;the appearance of the welding joints and the nondestructive flaw were tested,and the mechanical properties of the welded specimens and organizational structure were studied systematically.Results show that the electrode arc welding and CO2 gas shielded welding process can be used in the welding of Q345 B steel structure workshop;the welding quality can reach the national standard,but the CO2 gas shielded welding joints of tensile strength and elongation were higher than electrode arc welding joints,and the microhardness distribution more uniform.The impact of welding method on the organization of different parts of the welding joints was not tremendous,but each electrode arc welding joint area of the grain size were greater than the CO2 gas shielded welding head.The welding joints that welded by CO2 gas shielded arc welding with thermal input of 16 KJ·cm-1which had best comprehensive mechanical properties and homogeneous microstructures.The CO2 gas shielded arc welding with thermal input of 16 KJ·cm^-1were recommended for welding Q345 B steel structure workshop.