机电工程技术2026，Vol.55Issue(11)：26-29,51,5.DOI:10.3969/j.issn.1009-9492.2025.00122
20CrMo钢内齿圈跌落试验开裂失效分析
Failure Analysis of Cracking of 20CrMo Steel Internal Gear Ring in Drop Test
摘要
Abstract
Aiming at the cracking failure of 20CrMo steel internal gear ring in drop test,comprehensive analysis is carried out on the cracked gear ring by means of macroscopic observation,microstructure analysis,mechanical property test and fracture morphology observation.The crack source of the failed gear ring originated at the inner side,and the final fracture occurred at the outer side.It is indicated that an instantaneous impact load is applied to the outer side when the gear ring dropped to the ground,inducing compressive stress on the outer surface and tensile stress on the inner surface.Under the effect of tensile stress,crack initiation firstly occurred at the inner side,and the crack then rapidly propagated outward,eventually causing integral cracking of the internal gear ring.Fracture characteristic analysis shows that large structural stress existed inside the material.Both cleavage fracture and dimple fracture are observed at the fracture core,where the dimple fracture corresponded to the unquenched low-strength microstructure,proving that the core is not fully quenched.Matrix microstructure analysis demonstrates that the tempering process during heat treatment is extremely inadequate.Meanwhile,serious non-martensitic microstructure appears on the sample surface,which reduces the surface strength of the gear ring.The superposition and combined action of the above microstructure defects and stress state are the main causes for the cracking of the internal gear ring in drop test,which provides a basis for proposing targeted improvement measures and schemes for cracked gear ring parts.关键词
跌落试验/解理断口/组织应力/回火不充分/未淬透Key words
drop test/cleavage fracture/structural stress/insufficient tempering/incomplete quenching分类
矿业与冶金引用本文复制引用
钟喜春,金林奎,刘小阳,万珍平..20CrMo钢内齿圈跌落试验开裂失效分析[J].机电工程技术,2026,55(11):26-29,51,5.基金项目
广东省基础与应用基础研究基金项目(2023A1515240071) （2023A1515240071）
