Hypoeutectoid steel is heated to an intercritical temperature to produce a microstructure of about 30-50% austenite. The steel is then cooled as rapidly as feasible to a temperature below A.sub.s and held at temperature to transform the austenitic portion. Such transformation may occur either in the minimum of the pearlite region (˜1200° F) or in the bainite region (˜800° F).
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