Compact Cooling as an Alternative to Alloying for Production of DP/TRIP Steel Grades

摘要

The addition of expensive alloying elements is often needed to form the desired microstructures of DP and TRIP grades in hot rolled steel flat products. These alloying elements effectively modify the rate at which diffusional phase transformations occur; making it possible to produce the required microstructure within the constraints of a hot line's rolling speed, runout table length, and the heat extraction capabilities of its existing laminar cooling systems. This paper presents Compact Cooling systems as an alternative to this approach, whereby processing enhancements may enable new alloy designs and product strategies. Compact Cooling systems provide heat transfer rates that exceed those of conventional laminar cooling systems; hence they can bring about the required phase transformations with shorter runout table length requirements, reduce the levels of "hardenability" additions needed in the production of hot-rolled DP and TRIP grades, and enable the implementation of new microstructure/product concepts.