Research on the Bonding Interface of High Speed Steel/Ductile Cast Iron Composite Roll Manufactured by an Improved Electroslag Cladding Method

Abstract

In the present study, a new electroslag cladding method by using of the advanced current supplying mold technology was used for manufacturing the high speed steel (HSS)/ductile cast iron (DCI) composite roll. The graphite morphology, matrix microstructure, elements distribution, carbides morphology, and carbides composition have been investigated by means of optical microscope (OM), scanning electron microscope (SEM), and energy dispersive spectroscopy (EDS). With increasing distance from the HSS side, a transition of graphite morphology from naught to existence and from small and dispersed to large and nonuniform was obtained at the interface. It was closely related to the fact that graphite in DCI participated in the phase change and the roll core surface and its nearby positions was heated to a high temperature by the liquid slag during the whole electroslag cladding process. Due to the combined effects of melting and elements diffusion, a significant migration of the alloying elements have occurred through the line scan analysis. Based on this, different types of carbides with the morphology and composition were found at the bonding interface. In addition, no obvious slag inclusions, porosity, shrinkage and other defects at the bonding interface were found. Results of the tensile test also illustrated that the bonding interface had a good quality and it could fully meet the requirements of the roll.

Ironmaking and Steelmaking

“…A paper co-authored by scientists from Sweden and Egypt (El-Tawil et al [26]) investigated the thermal devolatilisation of different bio-coals for the purpose of reducing fossil CO 2 emission in the steel industry. Other international collaborations include France-Canada-Albania (Kanari et al [30]), Slovakia-Czech Republic (Neslušan et al [33]), China-Ukraine (Cao et al [1]), and China-UK (Ge et al [2]).…”

Research on hot deformation behaviour of as-cast W12Cr4V5Co5 steel

“…The called W12Cr4V5Co5 steel, which belongs to a kind of ultra-highstrength, high hardness high-speed steel, similar to the W2Mo9Cr4V2Co8 steel, is mainly used for fabricating cutting tools for processing high-strength steel, heat resistant steel, superalloy or other difficult-to-machine materials [3,4]. In recent years, high-speed steel by a cast and wrought processing route has attracted great attention in the fields of molds, rolls, bearings, etc., because of its excellent high-temperature resistance and wear resistance [5][6][7]. Consequently, it is a very meaningful exploration to provide for the promotion and application of this steel in more fields, which can simplify the production flowsheet and lower manufacturing costs.…”

Microstructure evolution of roll core during the preparation of composite roll by electroslag remelting cladding technology

“…The ESRC method developed by Jiang et al [15] is an innovative method for manufacturing a composite roll, which can effectively improve the solidification segregation, crystal structure of the outer layer, and realize the control of interfacial bonding temperature based on the electroslag remelting (ESR) and current supplying mold [16] technology. Cao et al [17] have carried out a study on the changes of graphite morphology, distribution, size, and matrix structure of the roll core (ductile cast iron) before and after the ESRC process. It illustrates that the graphite phase and matrix structure also change obviously due to the high temperature austenitization process that occurred in the roll core during the ESRC process.…”