Press hardening steels (PHS) for complex shapes

Press hardening steel has several names that refer to how it is used, including hot stamped, hot press forming (HPF), and hot formed (HF). PHS also has names based on its chemical composition, including hot-stamped boron, carbon-manganese-boron, and 22MnB5 boron.

The ultimate mechanical properties for PHS steels are set by the stamper, not the steel mill. Hot-stamped steels, “as delivered” by the steel mills, have a ferritic-pearlitic microstructure and when heated to 900°C by the fabricator, the steel converts to an austenitic microstructure. During the subsequent quenching process, the rate of cooling determines how much of the formed part is converted to the “full hard” (FH) martensitic microstructure.

PHS steels’ very high strengths allow for thin wall designs (“downgauging”) and therefore significant lightweighting of automotive crash components. Press hardening also enables UHSS steel to be formed into complex shapes.

• The greatest potential for vehicle lightweighting via the strongest strengths: up to 1380 MPa yield strength (R_p0.2) and 2040 MPa tensile strength (R_m).
• Maximize design flexibility and parts consolidation, with complex shapes readily formed at 900°C.
• A single PHS part can have multi-strength performance (e.g., energy transfer and energy absorption) via processes such as tailored tempering, tailored welded blanks (TWBs), and tailored rolled blanks (TRB).
• Excellent final shape accuracy, with little or no springback.