HR-2抗氢钢反挤球壳类锻件断口缺陷分析

Fracture Defect Analysis on Backward Extrusion of Spherical Shell Forgings for HR-2 Hydrogen Resistant Steel

由于HR-2抗氢钢棒料内存在氧化物、碳化物杂质及脆性相使得HR-2球壳的成形性能急剧降低,锻件表面产生局部裂纹。经取样分析,在断口表面观察到了较多的碳化物及氧化物颗粒。裂纹萌生周围的断口形貌出现崩碎现象,为典型的脆性断裂形貌。随着裂纹的扩展,断口形貌由崩碎的解理断面扩展到准解理面,最终在裂纹消失处发生了塑性断裂,并出现了大量规则的韧窝。

Because of the existence of oxides, carbides and brittle phase in the bar materials of HR-2 hydrogen resistance steel, the forming ability of HR-2 hydrogen resistance steel shell was drastically reduced, and the surface on the forgings generated cracks. Through sampling and analysis, a great amount of carbide and oxide particles were observed on the surface. The fracture morphology around crack arose the broken phenomenon. This was a typical brittle fracture morphology. With crack extension, the fracture morphology changed from cleavage plane to quasi-cleavage plane. The plastic fracture appeared at the disappearing place of cracks, and a large number of regular dimples produced.