B-2
Alloy SteelB-2
(ASTM A128). Nominal values—confirm mill certificate.
Chemical Composition (%)
| MO | 26 |
|---|---|
| FE | 2 |
| CR | 1 |
| C | 0.02 |
| SI | 0.1 |
| MN | 1 |
| P | 0.04 |
| S | 0.03 |
Mechanical Properties
Tensile:≥760 MPa;Yield:≥350 MPa;Elong:≥40%
Chinese Standard
ASTM A128 B-2
Available Forms
Bar,Plate
Uses
Tool and die steel for cutting, forming, punching and molding tools. Tungsten/molybdenum (≈0%/28%) give hot hardness and red-hardness for high-speed and hot-work tools. High chromium (≈1%) provides wear resistance and secondary hardening. Applied to blanks, punches, extrusion dies, shear blades, plastic-mold and cold-work tooling.
Heat Treatment
Powder/HSS: preheat 800–850 °C, austenitize 1180–1230 °C (salt or vacuum), quench, triple temper 540–570 °C to ≈64–66 HRC.
Precautions
Risk of quench cracking and distortion — use graded preheating, controlled cooling and multiple tempers. Avoid overheating the austenitizing temperature. Machine in the soft annealed condition; allow for dimensional change after heat treatment. Grind with coolant to prevent rehardening cracks.
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