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6.35毫米和12.7毫米(1/4和1/2英寸)厚HY-130钢焊件系分别采用了手弧焊(SMA)、熔化极气体保护焊(GMA)、电子束(EB)焊接和激光束(LB)焊接方法制造的。对焊件的焊缝金属和热影响区进行了硬度测定和金相检验。EB和LB焊件焊缝金属的硬度明显地高于SMA和GMA焊件的,其热影响区的硬度梯度也更陡。 SMA和GMA焊缝的金相组織由大量针状铁素体和少量贝氏体和马氏体组成;而EB和LB焊缝的则由大量马氏体和少量贝氏体组成。室温动态撕裂试验表明,焊接接头试样主要呈平面应力(斜断口)断裂。LB试样所具有的断裂韧性不仅高于其它焊缝的,而且可与基体金属的相比拟。发現SMA和GMA焊件中所存在的诱发冷裂敏感性的諸冶金状态和諸因素比EB和LB焊件中存在的更突出。检查动态撕裂(DT)试样的断口可发现:SMA和GMA焊件中有少量到中等程度的气孔;EB焊件中存在冷疤(未完全熔合);LB焊件中则有少许冷疤和氢脆的迹象。
The 6.3-mm and 12.7-mm (1/4 and 1/2 inch) thick HY-130 steels are welded by hand arc welding (SMA), GMA welding, EB welding and laser Beam (LB) welding method. The weldment weld metal and heat affected zone hardness and metallographic examination. EB and LB weldment weld metal hardness is significantly higher than the SMA and GMA weldment, the hardness of the heat-affected zone hardness gradient is also steeper. The microstructure of the SMA and GMA welds consists of a large amount of acicular ferrite and a small amount of bainite and martensite, while the EB and LB welds consist of a large amount of martensite and a small amount of bainite. The dynamic tearing test at room temperature shows that the specimens of the welded joint are mainly in the plane stress (oblique fracture) fracture. The fracture toughness of the LB specimens is not only higher than that of other welds but also comparable to the base metal. It was found that metallurgical conditions and various factors that induce cold cracking susceptibility present in SMA and GMA weldments are more prominent than those found in EB and LB weldments. Examination of the fracture of the dynamic tearing (DT) specimen revealed a small to moderate degree of porosity in the SMA and GMA weldments; cold scarring (incomplete fusion) in the EB weldment; a few cold scars in the LB weldment And hydrogen embrittlement signs.