关键词: 大变形量, 环件冷轧, 高碳钢, 微观组织

Abstract:

The cold ring rolling process of high carbon steel during large deformations was investigated herein. The deformation behaviour of the cold ring rolling process was analyzed by the finite element simulation method. The instruments like optical microscope and scanning electron microscope were employed to characterize the microstructure evolution of the cold rolled rings under large deformations. Results indicate that under smaller deformations, both of the outer and the inner sides of the ring exhibites higher plastic strain than that on the middle part and deformation firstly occurres in the outer side. It is observed that the most severe deformations occurre in the inner surface of the ring, the less severe deformations in the outer surface and  the least deformation in the middle part during the cold ring rolling process. With the deformation increasing, the inner side shows higher strain than that of the outer surface, and the location with the least strain shiftes to the peripheral layers. The ferrite matrix shows a clear direction along the rolling direction, and the distribution of cementite is more homogeneous with reduced carbide particles amount. Meanwhile, the shedding of the carbide particles is aggravated. When the deformations reach to 625%, the cold rolled ring reaches plastic limit with cracks firstly happening on the inner surface of the cold rolled ring.

Key words: large , deformation;cold ring rolling;high carbon steel;microstructure