25CrMo4

Alloy Steel

25CrMo4

(EN 10277). Nominal values—confirm mill certificate.

Chemical Composition (%)

C0.22
SI0.15
MN0.5
CR0.5
MO0.15
P0.035
S0.035

Mechanical Properties

Tensile:≥620 MPa;Yield:≥355 MPa;Elong:≥18%;RA:≥45%

Chinese Standard

EN 10277 25CrMo4

Available Forms

Bar,Plate

Uses

Low-alloy engineering steel with enhanced hardenability and strength from alloying elements. Chromium (≈0.65%) improves hardenability, wear and corrosion resistance. Molybdenum (≈0.2%) raises high-temperature strength and prevents temper embrittlement. Applied to gears, shafts, bolts, connecting rods, pressure parts and heavy forgings in automotive, energy and machinery sectors.

Heat Treatment

Austenitize at 820–870 °C (oil or water quench depending on section) and temper at 400–650 °C to the required strength/toughness balance.

Precautions

Weldable with standard procedures; preheat may be needed for thick sections or higher-carbon/ alloy grades. Protect from decarburization during heating (controlled atmosphere or protective coating).

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