A relatively new family of steel grades, called Hybrid Steels, is well-suited to meet the demands of high-stress, high-temperature applications in which mechanical and fatigue strength are critical. These steels are strengthened by an alloying philosophy combining precipitate phases and adding aluminum as an alloying element.
Steels have traditionally been divided into separate categories of tool steel, stainless steel and low-alloy engineering steel, as well as more sophisticated maraging steels. That changed in 2017 when Ovako launched its “Hybrid Steel” – a new family of grades with a new alloying philosophy. It challenges those long-established divisions by merging sets of properties from each category into one high-performance steel (Fig. 1).
The new steel family is called Hybrid Steel (HS) because it is strengthened by a combination of two well-established precipitate phases: alloy carbide and intermetallic. Furthermore, this steel family is made possible by a creative alloying philosophy that minimizes segregation. Most importantly, aluminum has been added in significant amounts, which has enabled a uniquely strong combination of attractive properties. This element reacts with nickel to form very small intermetallic precipitates, but nearer the surface it also helps to form an oxide barrier.
Check out the October 2020 issue of FORGE, featuring our cover story on "Fever Screening and Forging Quality". Other features include "Forging with Hybrid Steel", "FutureForge in Scotland: The Goldilocks Effect", and much more.