Microstructure Evolution and Mechanical Properties Improvement in Magnetic-controlled Electroslag Remelted Bearing Steel

Abstract

The transverse static magnetic field (TSMF) was introduced into the electroslag remelting (ESR) process to produce GCr15 steel ingots and the microstructure, non-metallic inclusions, chemical composition and mechanical properties of the ingots were analyzed to investigate the effect of TSMF during the ESR process. The transverse section of the ingots indicated that the application of a 130 mT static magnetic field resulted in a refined dendritic structure. The coverage ratio of the homogeneous crystallites area in the center of the transverse section increased to 52%. The metallic solid-liquid interface with different magnetic flux density (MFD) was recorded during ESR process. The depth of the metallic molten pool was 44.2 mm without the TSMF. When a 130 mT TSMF was applied, the molten pool became noticeably shallower (14.2 mm). And the oxide inclusions count in the scan area of 5.117 mm 2 decreased to 239 from 1 212. When the TSMF implemented, the tensile, friction and wear and Rockwell hardness properties of ingots showed a significant improvement. These results showed that the application of TSMF during the ESR process of GCr15 steel not only refine the dendritic structure, but also improve the efficiency of inclusion removal and mechanical properties.

Influence of Microsegregation on the TiN Inclusions Formation Behavior in a K418 Superalloy during the Continuous Unidirectional Solidification Process

“…Khiavi et al 10) showed that the total content of oxygen, nitrogen and hydrogen continuously decreased with the increasing refining time or the addition of calcium during vacuum induction refining. Guo et al 11) and Li et al 12) obtained high-purity ingots by applying a transverse static magnetic field (TSMF) during the electroslag remelting (ESR). The thickness of the liquid melting film (LMF) was decreased in the presence of the TSMF, meanwhile the kinetic conditions for inclusion removal were also enhanced.…”

“…( 12). 39) λ 2 = A f n t ................................. (12) where A = 6.79 × 10 − 6 m/s n and n = 0.43.…”

Morphology Control of Metal Pool and Eutectic Carbides in Electroslag Remelted M2 HSS with an External Axial Static Magnetic Field

“…Compared to the imposed alternating MF (electromagnetic stirring) or pulsed MF on the ESR process proposed by other researchers [36,37], because skin effect (due to the water-cooled mold) tends to happen with the application of alternating or cyclic MF, there is a significant benefit for static MF. Such technology is currently being investigated for a variety of steel grades including low-alloyed GCr15 bearing steel [38,39], medium-alloyed H13 die steel [40,41], and high-alloyed M2 HSS [42,43]. Guo et al [42,43] applied a transverse static MF (TSMF, with different magnetic flux densities) for regulating M2 HSS solidification upon ESR.…”