Materials and Design 24 (2003) 537–542 0261-3069/03/$ - see front matter  2003 Elsevier Science Ltd. All rights reserved. doi:10.1016/S0261-3069(03)00082-7 Wear behaviour of bulldozer rollers welded using a submerged arc welding process Behcet Gulenc *, Nizamettin Kahraman a, b ¨ ¸ ¸ Gazi University, Technical Education Faculty, Ankara, Turkey a Gazi University, Institute of Science and Technology, Ankara, Turkey b Received 3 December 2002; accepted 11 April 2003 Abstract The submerged arc welding process is commonly used due to its easy applicability, high current density and its ability to deposit a large amount of weld metal using more than one wire at the same time, especially in restoration of worn parts, which is of great importance to manufacturers. In this study, worn parts were welded using the submerged arc welding process. Various wires and fluxes were used for this purpose. These welded parts were subjected to wear tests under different loads, and changes in the hardness and microstructures were examined. A pin-on-disk wear test apparatus was used. The results showed that the hardest weld metal showed the highest wear resistance, while the least hard weld metal showed the least wear resistance. The weld hardness and wear resistance obtained were found to be dependent on the chemical composition of the weld wire and flux.  2003 Elsevier Science Ltd. All rights reserved. Keywords: Submerged arc welding; Wear; Flux; Hardness 1. Introduction Surface engineering is an economic method for the production of materials, tools and machine parts with required surface properties, such as wear and corrosion resistance w1,2x. When two surfaces contact, wear occurs on both surfaces. Individuals and industry tend to focus on the wearing surface that has the greatest impact on their own economic situation, and consider the other surface to be the abrasive w3x. Surface coating is employed to increase the wear and corrosion resistance of steels w4x. Surface treatments may improve the surface’s resistance to corrosion, impact breaks, or abrasive wear. However, no single surface treatment will give maximum resistance to all of these types of deterioration at the same time w5x. It is known that the abrasive wear rate can often be reduced by the application of hard materials. To char- acterise the abrasive wear behaviour, the transition from low wear to high wear with increasing hardness of the abrasive is very instructive w6x. *Corresponding author. Tel.: q90-312-212-6820x1706; fax: q90- 312-212-0059. E-mail address: behcetg@gazi.edu.tr (B. Gulenc). ¨ ¸ Hardfacing is a surface treatment to improve the surface properties of metals, in which a welding metal having excellent resistance to wear and oxidation is deposited onto the surface of a substrate. It is mainly applied to parts exposed to various wear environments in order to protect them and extend their life. The wear process of rollers is integrally affected by various fac- tors, such as abrasive wear, oxidation wear, cracking by thermal fatigue and heat impact, fatigue wear, and sticking of rolled material onto the roller surface. Wear also involves microscopic and dynamic processes occur- ring at interfaces between the roller and the rolled material, and is almost impossible to observe directly w7x. The wear of rolling mill rollers for continuous casting processes occurs under complicated service conditions and at elevated temperatures often causes early damages to the rollers. The wear behaviour and service life of the hardfacing clad layer are not only affected by the rolling conditions and temperature, but also by oxidation of the clad layers and cyclic thermal fatigue during continuous casting process. Various processes, such as spray and fusion, gas tungsten arc welding and sub-