Controlling centre segregation and shrinkage cavities without internal crack in as-cast bloom of steel GCr15 induced by soft reduction technologies

ABSTRACT

To investigate the alleviation technology of internal cracks, center shrinkage cavities and center segregation of as-cast bloom simultaneously, a three-dimensional finite element model was developed to calculate and analyze the strain fields and deformation behavior of as-cast bloom induced by soft reduction process. In the present work, a multi-stage mechanical soft reduction (MSR) has been developed to simultaneously alleviate center segregation and shrinkage cavities without internal cracks, which aims to provide theoretical basis for improving the internal quality of high carbon as-cast blooms induced by soft reduction technologies. According to the experimental results, the internal cracks were effectively alleviated and center shrinkage cavities were nearly eliminated by optimum designed experiments, the homogeneity and compactness of as-cast bloom can been remarkably improved in comparison with that induced by the conventional soft reduction process. The carbide size and bandwidth of the carbides in the hot-rolled wire were both decreased.

KEYWORDS:

• Internal cracks
• mechanical soft reduction
• shrinkage cavities
• segregation
• centre solid fraction
• high carbon bearing steel
• maximum equivalent strain
• deformation distribution

Acknowledgements

The present work is financially supported by The National Key Research and Development Program of China No. 2017YFB1103700. The authors are also grateful to Dr. Xuebing Wang in National Engineering and Research Center for Continuous Casting Technology for discussing on the accuracy of strain analysis in as-cast bloom during soft reduction operation.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by Instituto Nacional de Ciência e Tecnologia Centro de Estudos das Adaptações da Biota Aquática da Amazônia (BR ): [Grant Number 2017YFB1103700].