大型支承辊锻件内部夹杂性缺陷形成机理的FEM分析

FEM Analyses on Forming Mechanics of Inclusion Defects Inner Heavy Backup-Roll Forging

以大型Cr5钢支承辊锻件为对象,通过分析大型钢锭内部夹杂物种类及其变形特性,并考虑夹杂物与钢锭几何尺寸的实际比例关系,采用在钢锭内部分别预置球形塑性夹杂物和硬质夹杂物的方法,建立了大型钢锭高温锻造过程的非线性有限元模型。模拟结果表明:在锻造过程中,塑性夹杂物与钢锭基体金属协调变形,其三维形态呈"球形→椭球→扁平、细长片状"演变规律。结合硬质夹杂物周围基体金属流动规律、应力应变分布和物理模拟试验结果,对夹杂性裂纹缺陷的形成机理进行了分析,并给出了砧宽比和V形砧夹角对缺陷形态的影响规律。

By analyzing the species and detormanon characteristics the non--linear finite element model for forging process of ingot with central spherical plastic and hard inclusions was setup respectively to study the inclusion defects inner heavy Cr5 forged--steel backup --roll. Numerical simulation results show that the spherical plastic inclusion is forged to ellipsoid,plat and flake, deforms compatibly with ingot. Based on the metal flow law, stress and strain distribution around the hard inclusion, the forming mechanics of inclusion crack was discussed, and a physical simulation experiment was carried out to verify the presented conclusions. The influence law of tool width ratio and angle of V--shaped anvil on inclusion defects was also presented herein.