The flagship of the hot stamping family: a boron-alloyed steel that arrives soft, blankable and Al-Si coated, then leaves the die as a 1500 MPa martensitic crash structure — B-pillars, door beams, bumper rails.
Press hardening grades are named by strength after quenching. 22MnB5+AS defines the 1500 MPa class that most OEM crash structures are built from.
Usibor 1500 is ArcelorMittal's trade name for the same design intent — an Al-Si coated boron steel quenching to ~1500 MPa. Chemistry and coating weight differ slightly by source; the acceptance is the guaranteed post-quench mechanicals, not the brand.
Choose by governing print and certificate, not by name.Uncoated boron steel scales and decarburizes in the furnace — it needs shot blasting and often a second process step. The +AS coating stays protective through austenitizing, so parts leave the die clean and corrosion is handled downstream. The coating costs a little; the process freedom buys it back.
Choose +AS unless your line already treats uncoated surfaces.The 950/1300 class quenches to ~1300 MPa for parts that need a balance of strength and toughness. 22MnB5+AS goes to 1500 MPa where intrusion resistance dominates — the B-pillar and door-beam rung.
Choose 1500 for intrusion, 1300 for energy absorption.Boron is the hardenability insurance — without it, thin sections would not quench to full martensite. Titanium protects the boron. Confirmed on the MTC.
| Element | Typical range (%) |
|---|---|
| Carbon (C) | 0.19 – 0.25 |
| Silicon (Si) | 0.15 – 0.40 |
| Manganese (Mn) | 1.10 – 1.40 |
| Phosphorus (P) | ≤ 0.025 |
| Sulfur (S) | ≤ 0.010 |
| Chromium (Cr, typ.) | 0.15 – 0.35 |
| Titanium (Ti, typ.) | 0.020 – 0.060 |
| Boron (B) | 0.0008 – 0.0050 |
| Al-Si coating (each side) | ~10 µm typ. |
Typical, confirmed on MTC. Coating weight and intermetallic layer after forming are per governing spec. Coating thickness stated as supplied, before austenitizing.
The as-delivered column is what your blanking line sees; the quenched column is what the crash test sees.
| Property | As delivered (typ.) | After hot stamping & die quench (typ.) |
|---|---|---|
| Yield strength | 300 – 450 MPa | 1,000 – 1,200 MPa |
| Tensile strength | 500 – 650 MPa | ≥ 1,300 (typ. ~1,500) MPa |
| Elongation | ≥ 18% | ≥ 5% |
| Hardness | — | 430 – 500 HV (typ.) |
| Microstructure | Ferrite + pearlite | Martensite |
Indicative only. Post-quench values depend on austenitizing time/temperature, transfer time and die cooling — confirmed by trial on your part geometry.
Press hardening grades are sold under many names for the same property class — confirm before substitution.
| Standard / Source | Grade | Notes |
|---|---|---|
| EN (Europe) | 22MnB5 (base) | Confirm against EN 10083-3 / EN 10336 family |
| ArcelorMittal (trade) | Usibor® 1500 (approx.) | Same 1500 MPa Al-Si coated class |
| Baosteel / GB (China) | B1500HS (approx.) | Confirm against Q/BQB or GB press-hardening spec |
| ASTM / AISI (USA) | 15B22 (approx.) | Boron steel family — confirm hardenability and coating |
Approximate, confirm before substitution. Always compare guaranteed post-quench strength and coating class.
1.4–1.6 mm hot stamped with tailored tempering — a soft zone near the beltline for energy absorption, hard zones top and bottom for roof-crush and side-impact resistance. The +AS coating keeps the surface clean through the furnace.
1.2–1.8 mm closed-section beam that must not buckle in side impact. Quenched 22MnB5+AS holds the load path while the door skin (HC180YD+Z) manages the dent.
1.5–2.0 mm stamped rail connecting the crash cans. High-strength quenched steel keeps the section compact so the front overhang stays short without giving up intrusion performance.
1.2–1.6 mm hot stamped rail carrying roof-crush load. Laser-cut blanks from slit coil feed the press line; the Al-Si coating survives austenitizing without descaling between operations.
Read this before you order, so the material matches the hot stamping line.
Use 22MnB5+AS when you run a hot stamping line — austenitizing furnace, transfer robot, water-cooled die — and the part is an intrusion-critical structure: B-pillar, door beam, bumper rail, roof rail, floor tunnel. It is also the answer when a cold-formed high-strength part keeps failing crash targets and the section cannot grow.
Do not use it when there is no hot stamping line (the steel does not reach 1500 MPa any other way), when the part is a drawn outer panel (use SPCE or HC180YD+Z), or when the load is moderate and cold-formed SAPH440 or a DP grade carries it at lower total cost.
Pair it with HC180YD+Z outer panels in the same body module, SAPH440 for the non-hot-stamped chassis brackets, and 50WW470 electrical steel in the EV drivetrain program that surrounds the hot-stamped body.
Austenitize at 900–950 °C for 3–8 minutes, transfer in under ~8 seconds, form and quench in the water-cooled die at a cooling rate above ~27 °C/s — that path is what converts the soft blank into martensite at ~1500 MPa.
Coil is slit, then blanks laser-cut with edge quality that keeps the Al-Si coating intact — a damaged edge is a corrosion and decarb start point on the finished part.
Selective die heating creates soft zones in one part — hard at the ends, ductile in the middle — so one B-pillar does intrusion and energy absorption at once. Material and furnace must cooperate; we advise on the band.
Spot welding Al-Si coated press-hardened steel needs an adapted schedule, and sheared edges where coating is interrupted need protection in the body shop — we supply the material-side guidance with the certificate.
Stay with 22MnB5+AS while the crash targets hold and the line runs stable quench rates. Move down to the 950/1300 class (CR950/1300HS+AS) when a part needs more ductility than strength — energy absorption, not intrusion. Move across to uncoated boron steel only if your process already handles scale. If volume is too low to justify a hot stamping line, the honest answer is usually a cold-formed alternative like SAPH440 or a DP grade — we will say so rather than sell furnace steel to a press-only shop.
The furnace-to-die sequence, why cooling rate decides martensite, and what tailored tempering does to one part.
What +AS protects, how the coating changes welding, and how to manage exposed edges.
Grades matched to intrusion structures and body modules.
From press-hardening coil to ready-to-furnace blanks.
These grade families share material, processing or application territory with the topic on this page.
DP / TRIP / HSLA grades (HC180YD, HC260LA, DP590) combining strength with formability for lightweighting.
SPHC / Q235 / Q345 scale-free coils with oil coating, cost-effective for structural and tube applications.
Send thickness × width, blank dimensions (if applicable), coating weight, quantity and destination port. Our engineers reply within one working day.