40CrNiMoA
Alloy Steel40CrNiMoA
Premium 4340 Q&T steel. (GB/T 3077; equiv 40CrNiMoA / AMS 6414). Nominal values—confirm mill certificate.
Chemical Composition (%)
| C | 0.37 |
|---|---|
| SI | 0.17 |
| MN | 0.5 |
| NI | 1.25 |
| CR | 0.6 |
| MO | 0.15 |
| P | 0.025 |
| S | 0.025 |
Mechanical Properties
Tensile:≥980 MPa;Yield:≥835 MPa;Elong:≥12%;RA:≥55%;Akv:≥78 J
Chinese Standard
T 3077 40CrNiMoA
Equivalent Standards
AMS 6414
Applications
镍铬钼超高强钢。,Bar
Available Forms
Low-alloy engineering steel with enhanced hardenability and strength from alloying elements. Chromium (≈0.75%) improves hardenability, wear and corrosion resistance. Molybdenum (≈0.2%) raises high-temperature strength and prevents temper embrittlement. Nickel (≈1.45%) increases toughness and impact strength at low temperature. Applied to gears, shafts, bolts, connecting rods, pressure parts and heavy forgings in automotive, energy and machinery sectors.
Uses
Austenitize at 820–870 °C (oil or water quench depending on section) and temper at 400–650 °C to the required strength/toughness balance.
Heat Treatment
Preheat and control interpass temperature when welding; post-weld heat treatment or stress relief is recommended to avoid hard-zone cracking. Use low-hydrogen electrodes. Protect from decarburization during heating (controlled atmosphere or protective coating).
Precautions
40CrNiMoA
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