异形环轧件表面线状缺陷分析与仿真优化研究

Research on analysis and simulation optimization of linear defects on the surface of special-shaped ring rolled parts

1Cr21Ni5Ti双相不锈钢异形环锻件在切削加工过程中发现端面有线性缺陷,对端面表面肉眼可见的裂纹进行超声波探伤,发现裂纹可探的深度4mm~7.1mm。结合理论知识及实际生产设备、工艺及仿真进行分析:异形环端面的线状缺陷为辗环过程中的锻造折叠缺陷;缺陷产生机理是由扩孔、辗环过程中锻件当量轧比与设备结合不紧密,同时受到异形环件固有轧制缺陷趋势影响。该缺陷破坏了异性环件的金属流动完整性,降低了异性环件的整体性能。通过分析锻件缺陷产生的原因及时机,合理优化成形方案,结合粗车后上下端面的荧光检查和超声波探伤,可有效解决该类型缺陷锻件。

1Cr21Ni5Ti double-phase stainless steel special-shaped ring forgings have been found to have linear defects on the end surface during the cutting process. The visible cracks on the end surface have been subjected to ultrasonic inspection, and the depth of the cracks has been found to be 4 mm~7.1 mm. The following has been analyzed in combination with theoretical knowledge as well as actual production equipment,technology and simulation: the linear defect on the end face of the special-shaped ring is the forging and folding defect during the ring rolling process;the defect generation mechanism is the combination of the equivalent rolling ratio of the forging during the reaming and ring rolling process and the equipment is not tight, while it is also affected by the inherent rolling defect trend of special-shaped rings. This defect destroys the metal flow integrity of the heterosexual ring and reduces the overall performance of the heterocyclic ring. By analyzing the causes and timing of forging defects, the forming proposal has been reasonably optimized. In combination with the fluorescence inspection and ultrasonic inspection of the upper and lower end faces after rough turning, this type of defective forgings can be effectively solved.