20CrMnTiH齿轮轴脆断及裂纹原因分析  

Cause Analysis of the Fracture and Cracks of 20CrMnTiH Gear Shaft

作　　者：蔡朝华[1] 裴建华[1] 韩政[1] 翟正龙[1] 

机构地区：[1]莱芜钢铁集团有限公司,山东莱芜271104

出　　处：《山东冶金》2012年第6期45-47,共3页Shandong Metallurgy

摘　　要：针对齿轮轴用钢在锻打成形过程中出现脆断及机械加工件出现裂纹的情况，对断口进行SEM及EDS分析；对断口处的显微组织进行分析；对加工件裂纹部位取样进行SEM和EPMA分析。结果表明，断口含有铁的氧化物，被高温氧化；断口处显微组织为铁索体＋珠光体，心部存在各向异性，组织中有大量硫化物、氧化物等夹杂，夹杂物尺寸在1～15μm有少量孔洞，孔洞尺寸在5～10μm；裂纹两侧有明显的脱碳层。分析认为，裂纹是原材料在连铸或轧制过程中形成的，应在炼钢、连铸及轧制过程中进一步提高钢材质量。For the brittle fracture and cracks of gear shaft in the course of forging and machining, the fracture were analyzed by SEM and EDS; the microstructure near the fracture was studied and the samples taken on the crack site of the processing piece were analyzed by SEM and EPMA. The results showed that the fracture containing iron oxide oxidized at high temperature; the microstructure near the fracture was ferrite and pearlite with anisotropy existed in the core, mixed with 1-15 μ m inclusions of sulfide and oxide and little 5-10 μm cavities, and the two sides of the fracture had apparent decarburized layer. It is concluded that the cracks formed in the continuous casting and rolling process and improvements should be made further in the steelmaking, casting and rolling processes to enhance the quality of steel.

关 键 词：齿轮轴用钢 20CrMnTiH 脆断 裂纹 夹杂物 

分 类 号：TG115.2[金属学及工艺—物理冶金]