The success of microalloying low-carbon ferritic constructional steels with strong carbide formers such as V or Nb has been followed more recently by adopting a similar approach for medium-carbon forged engineering steels. The required strength levels can be achieved by direct cooling from the forging temperature to strengthened ferrite/pearlite microstructures rather than the traditional quenched and tempered martensite route. Transmission electron microscopy can be used to examine the roles of the microalloying additions, one of which is to precipitation harden both the proeutectoid ferrite and the pearlitic ferrite. Matching soaking and forging temperatures, arid cooling rate after forging, to the microalloying strategy should be practiced in order to achieve the best combinations of strength and toughness.
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