18CrNiMo7-6/17CrNiMo6/1.6587

18CrNiMo7-6 is a case hardening steel with high toughness. There are a number of variants with high cleanliness requirements. All variants  possess tighter composition ranges compared to the standard. One variant is produced with the quality class IQ (isotropic quality). This ensures a very low number of elongated sulphide inclusions which will give more isotropic properties. The high oxidic cleanliness will enable the steel to meet the same high cleanliness demands as for re-melted qualities.

Chemical Composition(%)

Standard	Grade	C	Mn	P	S	Si	Ni	Cr	Mo
EN 10084	18CrNiMo7-6	0.15-0.21	0.50-0.90	≤ 0.025	≤ 0.035	≤ 0.04	1.4-1.7	1.5-1.8	0.25-0.35
	1.6587

Application

18CrNiMo7-6 round Bar mainly used in mechanical parts, automobile parts, cement plants, power plants, mobile cranes and earth-moving equipment, paper mill, sugar mill, marine, wind gear, oil platform, fire protection, medical fields, industry equipment, collets, cams, rollers, bushes, spindles, and gears, etc.

Mechanical Property

Process	Tensile Strength Rm (Mpa)	Yield Strength Rp0.2 (Mpa)	Elongation A5 (%)	Area Reduction Ratio C (%)	Hardness (HB)
Q+T	980-1270	685 min	8 min	35 min	295-373

Heat Treatment Conditions

Annealing: Heat 18CrNiMo7-6 to 650-700°C. Cool in a furnace

Normalizing: 850-880°C. Cool in still air.

Hardening: Carburising: 880-980°C. Core Hardening: 830-870°C, water. Case Hardening: 780-820°C, water.
Tempering: 150-200°C.

Forging	925℃-1230℃
Normalizing	900℃-925℃
Full annealing	820℃-850℃
Tempering	150oC – 200oC