Increasing numbers of industrial components are being subjected to high surface stresses and dynamic loads, requiring the use of special high-performance steels. Where high surface hardness and excellent fatigue strength are required and when the material is also subjected to high temperatures, nitriding technology offers the best case hardening option.
|FOR REQUIREMENTS:||High Fatigue Nitriding Grade|
In this field, GKHW offers the best combination of core properties to withstand structural loads & damage tolerances and surface functions in the case hardened layer. The result on components gives one of the best solutions in the market for contact pressures and fatigue performances.
GKHW can also be used without nitriding and offers the triple advantage of an excellent combination of mechanical properties, high thermal fatigue and high thermal conductivity.
Benefits of GKHW
The use of GKHW covers all the gears design considerations and brings the highest value of this technology:
- Exceptional fatigue bending performance
- Very deep case requirement (0.8mm achieved in 120Hrs nitriding)
- Limited influence of ageing during nitriding on core properties
- Exceptional compromise of core hardness and damage tolerance
- Surface metallurgy with limited depth and favorable compound layer
- Weldable material (EBW for instance) giving the opportunity to avoid mechanical assembly
GKHW is used to produce nitrided parts which need to be extremely stable after hardening and tempering. It is particularly suitable for producing parts that undergo special nitriding.
GKHW has been successfully used for decades in the most critical mechanical components within Aerospace, Motorsports, injection systems, firearms, retaining rings, etc.
- Gears, spindles, machine-tool fittings
- Crankshafts, precision parts, aircraft parts
- Thrust rings, bearing races working up to 400 °C
Comparisons to Other Materials
|Grade||Technology||Case properties||Core properties||Lf case hardened material (Mpa/KSI)|
|Operating temperature (°F)||Top hardness (HRC)||Case depth (mm/in)||UTS (Mpa/KSI)||YS0,2 (Mpa/KSI)||K1c (MPa.Vm)|
|AMS 6475||Deep nitriding||840||65.50||0.45/.018||1240/180||1150/167||/||/|
|Heat Treatment||UTS||0.2% YS||E||KV||Surface Hardness|
|(MPa / Ksi)||(MPa / Ksi)||(%)||(J /ft.lb)||HRC|
|M50 VIM/VAR||1100°C / Gas, -75°C, 3 x 550°C||Through hardened to HRC: 60 – 63|
|9310 VAR & VIM/VAR||825°C / Oil, -75°C, 150°C||1150/167||900/131||14||140/103||60|
|M50NIL||1100°C / Oil, -75°C, 3 x 540°C||1400/203||1200/174||15||12/9||60|
|GKH Remelt (W) & VIM/VAR (YW)||920°C, Oil, 600°C||1250/181||1060/154||15||130/96||65.5|
|920°C, Oil, 640°C||1080/157||900/131||19||170/125||65.5|
|GKP Remelt (W) & VIM/VAR (YW)||940°C, Oil, 600°C||1430/207||1280/186||14||50/37||67|
|940°C, Oil, 640°C||1250/181||1075/156||16||80/59||67|
Bar: 5.512″ & 6.299″ (140mm & 160mm)