钢锭模耳轴断裂失效分析  

Failure Analysis of Ingot Mould Trunnion Fracture

作　　者：刘军利 任红娃 周志梭 Liu Junli;Ren Hongwa;Zhou Zhisuo(Chengdu Metallurgical Experimental Plant Co.,Ltd.,Chengdu Sichuan 610000,China)

机构地区：[1]成都冶金实验厂有限公司,四川成都610000

出　　处：《山西冶金》2025年第2期14-18,共5页Shanxi Metallurgy

摘　　要：在对某钢厂3.75 t钢锭模进行脱模作业时,钢锭模耳轴突然断裂,造成钢锭模掉落事故。钢锭模仅使用了1 a左右,虽然未造成人员受伤和财产损伤,但为了避免同类型问题再次发生,对掉落的耳轴进行了低倍、断口、成分、金相、拉伸等理化测试分析,并根据分析测试结果,采用Jmatpro7.0软件模拟了不同温度条件下耳轴材料和20钢的屈服强度值,再根据模拟的结果,校核了耳轴的设计尺寸,最终确认耳轴设计采用20钢的室温性能参数,该分析并未考虑高温使用时材料的强度降低的实际情况。此外,耳轴的制造用材料选择错误,实际使用的是接近45Mn材料,C和Mn元素含量过高,组织为珠光体+微量呈条带状分布的铁素体,导致材料强度过高,韧性不足。根据测试结果提出:在设计阶段,应根据材料高温阶段的性能数据进行设计,采用20钢时耳轴直径应大于140 mm以上,才可以保证耳轴具备足够的安全冗余度;在制造阶段,严格把控材料质量,避免错用材料,以及避免材料有严重的冶金缺陷。A 3.75 tons ingot mould in a steel plant was suddenly fractured by the trunnion of the ingot mould during demoulding operations,resulting in a falling ingot mould accident.The ingot mould was only used for about 1 year,although it did not cause any injury to personnel and property damage,but in order to avoid the same type of problem from happening again,the broken trunnion was analysed by macroscopic,fracture,composition,metallurgical,tensile and other physicochemical tests,and based on the results of the analyses,the yield strength values of the trunnion material and 20 steel were simulated using the Jmatpro 7.0 software under different temperature conditions,and based on the simulated results,the design dimensions of the trunnion were calibrated.Based on the simulation results,the design dimensions of the trunnion were calibrated,and it was finally confirmed that the design of the trunnion adopts the room temperature performance parameters of 20 steel and does not take into account the actual situation that the strength of the material decreases when it is used at high temperatures.In addition,the trunnion was manufactured from the wrong material,which was close to 45Mn.The high C and Mn elements,and the microstructure of pearlite+a trace amount of ferrite distributed in bands,led to excessive strength and insufficient toughness of the material.Based on the test results,it is proposed that in the design stage,the design should be based on the performance data of the material in the high temperature stage,and the diameter of the trunnion should be greater than 140 mm or more when 20 steel is used,in order to ensure that the trunnion has sufficient safety redundancy.In the manufacturing stage,the quality of the material should be strictly controlled to avoid misuse of the material and serious metallurgical defects in the material.

关 键 词：钢锭模 耳轴 断裂 屈服强度 脆断 强度校核 模拟 

分 类 号：TG115[金属学及工艺—物理冶金]