高强韧吊臂用管焊接接头的组织与性能

Microstructure and Characteristics of Hi-strength/Hi-toughness Welded Joint of Pipe for Crane Jib Service

提出了一种含W元素的BG890QL高强管,并将其焊接接头的金相组织、疲劳性能、拉伸性能和冲击韧性与不含W元素Q890L钢管的进行对比。结果表明:虽然两种材质钢管的常规力学性能相近,但是BG890QL的疲劳性能更优;焊接接头区域皆可分为焊缝区、粗晶区、细晶区以及回火软化区;W元素的添加改变了焊接过程中的相变行为,使得焊缝及热影响区的晶粒细小,从而提高了BG890QL高强管焊缝热影响区的综合力学性能。

Described here in the paper is a tungsten-containing high-strength/high-toughness BG890QL steel pipe. And the welded joint of the said pipe is compared with that of the tungsten-free Q890L steel pipe in terms of metallographic structure, fatigue behavior, tensile property and impact toughness, etc. The results reveal the following facts. Although mechanical properties of the two kinds of steel pipes are similar, the fatigue behavior of the BG890QL pipe is much better; the welded joint areas of both pipes have the same zones, i.e., the weld zone, the coarse grain zone, the fine grain zone and the tempering-softening zone; addition of W element changes the phase transformation behavior during the welding process, which makes the grains of weld and heat affected zone finer, and thus the overall mechanical properties of the weld and heat affected zone are improved.