The High Strength Cold Forging Applications of a New Low Carbon Multi-Phase Steel

A new microalloyed, multi-phase low carbon steel has been developed as an alternative to the QT steels which have traditionally been used in the fabrication of high strength cold forged products. The benefits of this new steel include: (1) the elimination of spheroidize annealing prior to cold forming; (2) the elimination of the QT heat treatment after the deformation; and (3) the ability to achieve in the final component yield strengths of desired levels, high fatigue resistance and very high notch toughness. The excellent properties exhibited by this steel are a direct result of the advanced thermomechanical or controlled processing of the austenite during bar and/or rod rolling. This paper will first briefly review the physical metallurgy of this steel as it pertains to cold forming. This will be followed by a review of industrial trials where various components have been cold forged from this steel.