Scale (or iron oxide) forms on the surface of steel during continuous casting, slab reheating and subsequent rolling process. For heat-treated products, especially for quench-and-tempered products, scale can reduce heat transfer efficiency during quenching. Therefore, scale is deemed to be undesirable for the quenching process and should be blasted off prior to austenitization. Although scale formation at high temperature has been studied extensively, it is still not completely clear how the steel chemistry and slab reheating atmosphere impact scale formation and its adherence to the steel. This article discusses scale formation on four steels in a simulated slab reheating condition with different excess oxygen levels.

Tempering is a well-known process which is usually used to improve the ductility and toughness of steel produced by a quenching process. Similarly, through tempering, the mechanical properties of as-rolled products can be altered. However, there is limited information available regarding the tempering response of as-rolled low-carbon microalloyed steels. In the present study, the effects of tempering on three low-carbon microalloyed steels were examined. The benefits of tempering for these steels are presented.