20CrNiMo

Alloy Steel

20CrNiMo

Carburizing gear steel. (GB/T 3077; equiv GB 20CrNiMo / AISI 8620). Nominal values—confirm mill certificate.

Chemical Composition (%)

C0.17
NI1.5
MO0.2

Mechanical Properties

Tensile:≥885 MPa;Yield:≥735 MPa

Chinese Standard

T 3077 20CrNiMo

Applications

镍钼渗碳钢。,Bar

Available Forms

Carburizing (case-hardening) steel with low carbon core for toughness and a hard, wear-resistant surface after carburizing. Used for gears, camshafts, pinions, spline shafts, bushings and transmission parts subjected to fatigue and surface wear.

Uses

Typically normalized (880–920 °C, air cool) or carburized (900–930 °C) for case-hardening grades, then quenched and tempered at 150–200 °C. Carburize 900–930 °C, direct/intake quench, temper 150–200 °C; useful case depth 0.5–1.5 mm.

Heat Treatment

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). Machine the core stock before surface hardening; leave grinding allowance for the hardened case.

Precautions

GB 20CrNiMo / AISI 8620

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