18CrNiMo7-6 | DIN 1.6587 Case Hardening Steel-EN10084

As an alloy structural steel, 18CrNiMo7-6 has high strength and high toughness. Its strength is mainly due to the high chromium content in its composition, while the addition of nickel and molybdenum helps improve its toughness and corrosion resistance. In addition, its hardenability and heat treatability are also well improved, making it easier to control and adjust during processing and manufacturing.

Due to these properties, 18CrNiMo7-6 is mainly used to manufacture important parts requiring high strength and corrosion resistance, such as gears, shafts, and connecting rods in the automotive, aerospace, and energy fields.

18CrNiMo7-6 VS 17CrNiMo6 CHEMICAL COMPOSITION

Standard	Grade	C	Si	Mn	P	S	Cr	Ni	Mo
EN 10084	18CrNiMo7-6	0.15-0.21	≤0.4	0.5-0.9	≤0.025	≤0.035	1.5-1.8	1.4-1.7	0.25-0.35
DIN 17210	17CrNiMo6	0.15-0.20	≤0.4	0.4-0.6	≤0.035	≤0.035	1.5-1.8	1.4-1.7	0.25-0.35

18CrNiMo7-6 STEEL RELATED STANDARD & EQUIVALENT GRADE

China: 17Cr2Ni2Mo

Germany: 17CrNiMo6

ISO: 18CrNiMo7

Finland:511

18CrNiMo7-6 STEEL FORGING

Initial Forging Temperature：1150-1200℃
Final Forging Temperature：>850℃
Forging Ratio：above 4:1
Cooling Method After Forged:As a low carbon alloy carburizing steel,18CrNiMo7-6 steel is is highly sensitive to white spots, which means that dehydrogenation heat treatment must be done immediately after forging.Therefore, annealing heat treatment and slow cooling in the furnace are recommended.

18CrNiMo7-6 STEEL HEAT TREATMENT

Temperature Selection for Different Types of Heat treatment for 18CrNiMo7-6 steel

Annealing:800–850°C,Cooling in furnace,hardness below 229HBW
Carburizing:880-980°C
Core-hardening:830-870°C
Case-hardening:780-820°C
Tempering:150-200°C

18CrNiMo7-6 steel Hardenability Limits

Jominy Quenching Test Curve For 18CrNiMo7-6 Steel

Jominy Quenching Test Curve For 18CrNimo7-6 Steel

Quenching at 860°C

X:Distance from quenched end,in mm

Y:Hardness,HRC

1: HH level

2: HL level

3: H level

Distance from quenched end mm		1.5	3	5	7	9	11	13	15	20	25	30	35	40
18CrNiMo7-6+HH	HRC Max	48	48	48	48	47	47	46	46	44	43	42	41	41
18CrNiMo7-6+HH	HRC Min	43	43	42	41	40	40	39	38	36	35	34	33	33
18CrNiMo7-6+HL	HRC Max	45	45	45	45	44	43	42	42	40	39	38	37	37
18CrNiMo7-6+HL	HRC Min	40	40	39	38	37	36	35	34	32	31	30	29	29

18CrNiMo7-6 Steel Mechanical Property with Carburized,Quenched and Tempered Condition

Sample Size mm	Tensile Strength Mpa	Yield Strength Mpa	Elongation %	Reduction of Area %	Impact Charpy-V J	Quenching Hardness HRC
≤30	1080-1320	≥785	≥8	≥35	≥41	Carburized 55-62
30-63	980-1270	≥685	≥8	≥35	≥41	Carburized 55-62