Available Shapes
722M24 Nitriding Steel
722M24 is a chromium-molybdenum-based engineering steel grade from Thames Stockholders which is often delivered in hardened and tempered condition. It benefits from good wear resistance and high fatigue strength. This can increase the tensile strength by up to 1075 N/mm². Nitriding yields a hard and wears resistant casing resulting in an engineering material that delivers good fatigue and shock resistance. The nitriding process is usually performed at a comparatively low temperature which brings about a scale-free surface with minimal distortion.
722M24 can function in atmospheres of up to 500 °C before any loss in surface hardness is noticed. 722M24 is delivered in the hardened and tempered ‘T’ condition. This nitriding steel also offers a good combination of toughness and ductility. When supplied in the ‘T’ condition, 722M24 is ideal for applications necessitating high creep resistance and high tensile strength.
722M24 has become a widely used engineering material in industries such as automotive, textiles, and aerospace. It is also widely used by billet crankshaft manufacturers.
Applications
Analysis
Forging
Annealing
Hardening
Tampering
Typical Mechanical Properties*
Applications
722M24 is delivered in the ‘T’ condition. Examples of commercial application are listed below: Crankshafts and gears Spindles and pins Gear wheels Compressor discs Cams, pinions, and gudgeon pins Used in aerospace, automotive, textile, and general engineering applications
Analysis
Carbon | 0.20-0.28% | Chromium | 3.00-3.50% |
Manganese | 0.45-0.70% | Molybdenum | 0.45-0.65% |
Silicon | 0.10-0.40% | Sulphur | 0.040% max |
Phosphorous | 0.035% max |
Forging
Preheat the steel carefully, then raise the temperature to 850-1200°C for forging. Do not forge below 850°C. After forging 722M24 alloy steel, cool slowly in still air.
Annealing
Heat the 722M24 slowly to 680-700°C. Cool in air.
Hardening
722M24T is supplied ready heat treated. If further heat treatment is required annealed 722M24 should be heated slowly to 880-910°C and after adequate soaking at this temperature quench in oil/polymer or water. Temper as soon as tools reach room temperature.
Tampering
Carefully heat to a suitable temperature selected by reference to a tempering chart or table (usually between 570-700°C), soak at the temperature for two hours per 25mm of ruling section, then allow to cool in the air.
Typical Mechanical Properties*
Condition | Tensile N/mm² | Yield N/mm² | Elongation % | Izod KCV J | Hardness Brinell |
---|---|---|---|---|---|
S | 775-925 | 525 | 14 | 16 | 223-277 |
T | 850-1000 | 650 | 13 | 35 | 248-302 |
U | 925-1075 | 755 | 12 | 42 | 269-331 |
(*subject to ruling section)