Press-Hardened Steel (PHS)

Press-hardened steel (PHS), also called boron steel or hot-stamped steel, is the dominant crash-structure grade in modern body-in-white. Blanks are heated into the austenite range, formed in a cooled die and quenched to a martensitic microstructure — the process behind Usibor-class A-pillars, B-pillars, roof rails and bumper beams. PHS is a process-and-grade family, not a synonym for the library's Ultra-High Strength Steel umbrella. UHSS also covers dual-phase, TRIP and cold-stamped martensitic sheets; this page is specifically the hot-stamped boron steels that arrive as Al-Si or zinc-coated coil and leave the press as fully hardened crash members. Because formability is taken in the hot state, complex geometries are possible at strengths that would split in a cold die. Soft-zone and tailored-temper variants are used where some ductility is needed next to a hard intrusion zone. The material remains a recyclable steel.