Application of High Strength Microalloyed Steel in a New Automotive Crankshaft Young Sang Ko, Jin Woo Park, Hyounsoo Park, Jong Dae Lim Hyundai and Kia Motor Company Research and Development Division 722-1, Changduk Whasung, Kyunggi 445-850 Korea Tel: 82-31-368-7355 Fax: 82-31-368-7355 E-mail:
[email protected],
[email protected] David K. Matlock Advanced Steel Processing and Products Research Center Colorado School of Mines Golden, CO 80401 Tel: 303-273-3025 Fax: 303-273-3016 E-mail:
[email protected] Key Words: microalloyed steel, forging, crankshaft INTRODUCTION Applications of steels for new forged automotive components require a complete understanding of material properties and design requirements. Today there are many potential combinations of steel bar compositions and surface hardening methods that can be employed. Generally plain carbon steels, alloy steels, and microalloyed steels are used for forged bar applications and nitriding, induction hardening, or fillet rolling are applied to selected highly-stressed areas to produced optimum performance. At the preliminary stage in the design of a new model several factors must be considered. Cost, infrastructure requirements, and lead time are considered together to ensure proper selection of material alloy and hardening method. Currently many crankshaft forging companies have eliminated quenching and tempering (Q&T) heat-treatment facilities from their shops, and thus in the production of crankshafts it is not easy to apply alloy steels that require Q&T processing. The use of microalloyed steels in crankshafts have been shown to be a viable alternative to Q&T steels, particularly in engines that require significant improvements in performance [1].