01 What is sulfuretted nitrification?

In addition to the conventional gas soft nitriding treatment, this treatment produces a sulfide layer on top of the nitride compound layer on the surface layer.

• The sulfide layer is relatively soft and improves solid lubricity, galling resistance, and seizure resistance.
• Nitride compound layer improves wear resistance.
• Nitrogen diffusion layer improves surface fatigue resistance.

RAW MATERIALS USED: N2, NH3, NM GAS (H2S + N2 MIXED GAS), C2H2

Processing time: 3 to 5 hr

02 Hardness distribution of gas-immersion sulfur nitriding

SKD61

SURFACE HARDNESS HV1100
INTERNAL HARDNESS HV470
Hardened layer depth (HV750UP) 0.2mm
Diffusion layer depth (HV500UP) 0.28mm

FCD700

SURFACE HARDNESS HV910~930
INTERNAL HARDNESS HV320~340
Hardened layer depth (HV370UP) approx. 50 μm

SCM435

SURFACE HARDNESS HV770
INTERNAL HARDNESS HV290
Hardened layer depth (HV450UP) 0.12mm
Diffusion layer depth (HV370UP) approx. 50 μm

S45C

SURFACE HARDNESS HV730
INTERNAL HARDNESS HV180~195
Hardened layer depth (HV350UP) 0.15mm

03 Gear Noise Reduction Effect of Immersion Nitriding

The sulfide layer has good penetration (galling resistance and seizure resistance), which also reduces gear noise.

04 Comparative data on seizure resistance of immersion nitriding

Comparison of seizure resistance

05 We explain the technology of sulfur dioxide nitriding in this video.