铁路Ⅱ型弹条制造过程中的开裂分析

Cracking analysis on Ⅱrailway spring bar during manufacturing process

通过现场考察、显微组织分析与相变点测定,分析了铁路Ⅱ型弹条在制造过程中产生裂纹的原因。结果表明弹条出现裂纹的主要原因是在弹条热挤压成形过程中,在铁素体与奥氏体两相区内挤压产生过大变形应力使弹条开裂。在热加工过程中产生的热应力、接触应力及相变应力也助长裂纹的形成。

Reasons of cracks in Ⅱ spring bar during the manufacturing process were analyzed through investigation,microstructure observation and phase transformation temperature examination.The results show that the main reason of the cracks in the spring bar is that the hot extrusion stress forming during the processing,between ferrite and austenite two-phase region.Meanwhile,the thermal stress,contact stress and phase transformation stress during the hot processes also promote the cracking.