Nickel Chromium Molybdenum Steel for Machine Structural use

Ni Cr. Mo. steel is a material that has Mo. element (<1.0%) added, to acquire its strength and toughness and become the most excellent steel type among all kinds of structural steel.This steel has good yield strength and resistance to stubbornness, good hardening performance, high toughness, high wear resistance and impact resistance.

㈠ Chemical Composition
⒈ Carbon (C): 0.2% - 0.4%
⒉ Nickel (Ni): 1.0% - 3.5% - Provides high toughness and good corrosion resistance.
⒊ Chromium (Cr): 0.5% - 1.5% - Enhances wear resistance and corrosion resistance.
⒋ Molybdenum (Mo): 0.2% - 0.5% - Increases high-temperature strength and toughness, improves hardenability.
⒌ Manganese (Mn): 0.3% - 0.8% - Increases strength and hardness.
⒍ Silicon (Si): 0.15% - 0.5% - Improves strength and hardness.
⒎ Sulfur (S) and Phosphorus (P): Low content, each below 0.035%, to minimize adverse effects on steel properties.

㈡ Properties
⒈ High strength and toughness: Addition of nickel and chromium significantly improves the strength and toughness of the steel, allowing it to perform well in high-strength applications.
⒉ Excellent corrosion resistance: Combination of nickel and chromium gives the steel excellent corrosion resistance, especially in harsh environments.
⒊ Good heat resistance: Presence of molybdenum allows the steel to maintain good strength and stability at high temperatures.
⒋ Good hardenability: Addition of nickel and molybdenum improves the steel's hardenability, enabling more uniform hardness distribution during heat treatment.
⒌ High wear resistance: Chromium enhances the steel's resistance to wear, suitable for use in high-wear environments.
⒍ Weldability: Nickel-chromium-molybdenum steel exhibits good weldability but requires proper preheating and post-weld heat treatment to prevent welding cracks.
⒎ Machinability: Has good machinability, suitable for applications requiring high wear resistance.

㈢ Heat Treatment
⒈ Quenching:
Heating to austenitizing temperature (850-950°C), then rapidly cooling (typically in oil or water) to increase the steel's hardness and strength.

⒉ Tempering:
Heating the quenched steel to tempering temperature (500-700°C), then slow cooling to reduce quenching stress and increase toughness.

⒊ Normalizing:
Heating to slightly above austenitizing temperature (850-950°C), then cooling in air to achieve uniform steel structure and improve mechanical properties.

⒋ Annealing:
Heating to appropriate temperature (650-750°C), then slow cooling to improve machinability and stability.

These translations aim to accurately convey the technical details and characteristics of the steel and its heat treatment processes.

Product Applications

⒈Aerospace industry: Used for manufacturing high-strength structural components, engine parts, and airframe components.
⒉Automotive industry: Used for manufacturing high-stress components such as crankshafts, connecting rods, gears, and bearings.
⒊Energy industry: Used for manufacturing high-pressure boilers, heat exchangers, pressure vessels, and nuclear power equipment.
⒋Mechanical manufacturing: Used for manufacturing various high-strength machinery equipment and components.
⒌Oil and gas industry: Used for manufacturing drilling equipment, high-pressure pipelines, and other components requiring high strength and corrosion resistance.

SNCM420

SNCM420 is a commonly used low-carbon alloy carburizing stee

MORE
SNCM420

SNCM420 is a commonly used low-carbon alloy carburizing steel, incorporating nickel (Ni), chromium (Cr), and molybdenum (Mo) elements. After carburizing heat treatment, the surface exhibits high hardness, wear resistance, and contact fatigue strength, while maintaining good toughness in the core to withstand high impact loads.


[Various Country Standards]
Japan (JIS): SNCM420 (JIS G4103)
USA (ASTM): 4320
Europe (EN): 20MnCr5


[Characteristics]
High strength: Suitable for parts requiring medium to high loads and high strength.
Good toughness: Attains good toughness and ductility after heat treatment.
Wear resistance: Typically used for parts requiring wear resistance.


[Heat Treatment Conditions]
Annealing: Furnace cooling at 850℃
Normalization: Air cooling at 850-900℃
Quenching: 1st quench at 850-900℃ in oil, 2nd quench at 770-820℃ in oil
Tempering: Air cooling at 150-200℃


[Mechanical Properties]
Tensile strength (kgf/mm²): ≥980
Elongation (%): ≥15
Reduction of area (%): ≥40
Impact value (J/cm²): ≥69
Hardness (Hb): ≥293~375


[Applications]

① Bearing parts: Such as bearing seats, bushings, etc., due to high strength and wear resistance, capable of withstanding high loads and wear.

② Gears: Including various transmission gears, gearbox gears, etc., requiring high torque and wear resistance.

③ Connecting components: Such as bolts, nuts, connecting rods, etc., ensuring structural safety and reliability in mechanical structures.

④ Tools: Especially tools requiring abrasion resistance and high strength, such as cutting tools, molds, etc.

⑤ Mechanical parts: Various mechanical components, such as machine parts, automotive parts, construction machinery parts, etc., used to enhance component life and reliability.

Close
SNCM616

SNCM616, is also called high-toughness steel, has the best w

MORE
SNCM616

SNCM616, is also called high-toughness steel, has the best wear-resistance among all kinds of Ni. Cr. Mo. steel; it is one of the materials that can undergo tensile strength above 1180 and other the most critical conditions. SNCM series steel contain lower carbon which makes them relatively high at Mo. content. Mo. is an additive that can affect material strength at high temperature and hardenability (curling resistance).

Close
8660、8660+V

[Various Country Standards]
USA (ASTM

MORE
8660、8660+V

[Various Country Standards]
USA (ASTM) 8660: ASTM A29/A29M 8660+V: ASTM A304/A304M


[Characteristics]
Low alloy properties: Contains a small amount of alloying elements to enhance hardness and strength.
High strength: Suitable for parts with medium to high load and strength requirements. Good hardenability: Achieves good hardenability and hardness after heat treatment.


[Mechanical Properties]
Tensile strength: Typically above 1000 MPa.
Yield strength: Typically above 800 MPa.
Elongation: Approximately 10% or more.
Hardness: Depends on specific heat treatment, generally above 200 HBW.


[Heat Treatment Conditions]
Annealing: Typically conducted at 870-925°C, followed by air cooling.
Quenching: Oil quench or water quench to achieve appropriate hardness.
Tempering: Usually carried out at 150-200°C to improve toughness and reduce brittleness.


[Applications]
Mechanical parts: Such as bolts, nuts, bearings, gears, etc.
Tools: Especially parts requiring wear resistance and high strength.
Automotive parts: Such as gearbox components, drive shafts, etc.

Close
SNCM220 White Cross

SNCM220(8620), one of the common carburized low-carbon alloy

MORE
SNCM220 White Cross

SNCM220(8620), one of the common carburized low-carbon alloy that has Ni. Cr. Mo. elements added to, has high surface roughness, wear-resistance and contact fatigue strength in the meantime keeping its good toughness for undergoing impact loads.

SNCM220 is widely applied to the fabrication of car bearings, shafts, gear, axial parts, pistons, automobile assembly parts, machinery accessories which are more critical for impact loads, wear-resistance and the hardness of the material surface.

SNCM220(JIS Japan), 8620(SAE/AISI U.S.), 21NiCrMo2/1.6523(DIN German), 20CrNiMo (GB China), SNCM220(CNS Taiwan), 20NiCrMo2(ISO International Standard).

Close
SNCM220白十字

SNCM220(8620), one of the common carburized low-carbon alloy

MORE
SNCM220白十字

SNCM220(8620), one of the common carburized low-carbon alloy that has Ni. Cr. Mo. elements added to, has high surface roughness, wear-resistance and contact fatigue strength in the meantime keeping its good toughness for undergoing impact loads.

SNCM220 is widely applied to the fabrication of car bearings, shafts, gear, axial parts, pistons, automobile assembly parts, machinery accessories which are more critical for impact loads, wear-resistance and the hardness of the material surface.

SNCM220(JIS Japan), 8620(SAE/AISI U.S.), 21NiCrMo2/1.6523(DIN German), 20CrNiMo (GB China), SNCM220(CNS Taiwan), 20NiCrMo2(ISO International Standard).

Close
SNCM439 Blue Cross

SNCM439 is a kind of Ni. Cr. Mo. steel for structures that c

MORE
SNCM439 Blue Cross

SNCM439 is a kind of Ni. Cr. Mo. steel for structures that contains 1.60~2.00% Ni, 0.60~1.00% Cr., 0.15~0.30% Mo and 0.36~0.43% carbon content; it is similar to AISI-4340.

Because SNCM 439 contains elements such as Ni., Cr. and Mo. which can enhance hardenability, it can be hardened effectively up to 70mm diameter (hardened depth can be nearly 35mm). The excellent attribute of strength and toughness come from quenching and tempering processes.

SNCM439 is a kind of high-toughness steel often applied to the fabrication of gears, mid-small size high-strength shafts, cranks, pistons, automobile assembly parts, various machinery, high-strength bolts and nuts.

Close
SNCM439 Blue Cross

SNCM439 is a kind of Ni. Cr. Mo. steel for structures that c

MORE
SNCM439 Blue Cross

SNCM439 is a kind of Ni. Cr. Mo. steel for structures that contains 1.60~2.00% Ni, 0.60~1.00% Cr., 0.15~0.30% Mo and 0.36~0.43% carbon content; it is similar to AISI-4340.

Because SNCM 439 contains elements such as Ni., Cr. and Mo. which can enhance hardenability, it can be hardened effectively up to 70mm diameter (hardened depth can be nearly 35mm). The excellent attribute of strength and toughness come from quenching and tempering processes.

SNCM439 is a kind of high-toughness steel often applied to the fabrication of gears, mid-small size high-strength shafts, cranks, pistons, automobile assembly parts, various machinery, high-strength bolts and nuts.

Close
SNCM439 Blue Cross

SNCM439 is a kind of Ni. Cr. Mo. steel for structures that c

MORE
SNCM439 Blue Cross

SNCM439 is a kind of Ni. Cr. Mo. steel for structures that contains 1.60~2.00% Ni, 0.60~1.00% Cr., 0.15~0.30% Mo and 0.36~0.43% carbon content; it is similar to AISI-4340.

Because SNCM 439 contains elements such as Ni., Cr. and Mo. which can enhance hardenability, it can be hardened effectively up to 70mm diameter (hardened depth can be nearly 35mm). The excellent attribute of strength and toughness come from quenching and tempering processes.

SNCM439 is a kind of high-toughness steel often applied to the fabrication of gears, mid-small size high-strength shafts, cranks, pistons, automobile assembly parts, various machinery, high-strength bolts and nuts.

Close

Steel data

Standard Code Spec No. Material No. Mark
CNS 3271 SNCM220
JIS G4103 SNCM220
AISI 8620
CNS 3271 SNCM420
JIS G4103 SNCM420
AISI 4320
CNS 3271 SNCM439
JIS G4103 SNCM439
AISI 4340
CNS 3271 SNCM815
JIS G4103 SNCM815
SAE G86600 8660
CNS 8660+V
(C)% (Si)% (Mn)% (P)% (S)% (Ni)% (Cr)% (Mo)% (Cu)% (V)%
0.17~0.23 0.15~0.35 0.6~0.9 ≦ 0.03 ≦ 0.03 0.4~0.7 0.4~0.65 0.15~0.3 ≦ 0.3
0.17~0.23 0.15~0.35 0.6~0.9 ≦ 0.03 ≦ 0.03 0.4~0.7 0.4~0.65 0.15~0.3 ≦ 0.3
0.18~0.23 0.15~0.3 0.7~0.9 ≦ 0.035 ≦ 0.04 0.4~0.7 0.4~0.6 0.15~0.25
0.17~0.23 0.15~0.35 0.4~0.7 ≦ 0.03 ≦ 0.03 1.6~2 0.4~0.65 0.15~0.3 ≦ 0.3
0.17~0.23 0.15~0.35 0.4~0.7 ≦ 0.03 ≦ 0.03 1.6~2 0.4~0.65 0.15~0.3 ≦ 0.3
0.17~0.22 0.15~0.3 0.45~0.65 ≦ 0.035 ≦ 0.04 1.65~2 0.4~0.6 0.2~0.3
0.36~0.43 0.15~0.35 0.6~0.9 ≦ 0.03 ≦ 0.03 1.6~2 0.6~1 0.15~0.3 ≦ 0.3
0.36~0.43 0.15~0.35 0.6~0.9 ≦ 0.03 ≦ 0.03 1.6~2 0.6~1 0.15~0.3 ≦ 0.3
0.38~0.43 0.15~0.35 0.6~0.9 ≦ 0.035 ≦ 0.035 1.5~2 0.7~0.9 0.2~0.3
0.12~0.18 0.15~0.35 0.3~0.6 ≦ 0.03 ≦ 0.03 4~4.5 0.7~1 0.15~0.3 ≦ 0.3
0.15~0.35 0.15~0.35 0.3~0.6 ≦ 0.03 ≦ 0.03 4~4.5 0.7~1 0.15~0.3 ≦ 0.3
0.56~0.64 0.15~0.35 0.75~1 ≦ 0.035 ≦ 0.04 0.4~0.7 0.4~0.6 0.15~0.25
0.56~0.64 0.15~0.35 0.75~1 ≦ 0.035 ≦ 0.04 0.7~0.6 0.4~0.6 0.15~0.25 0.15~0.25