Steel stainless powder metallurgy N690CO, with the addition of molybdenum, vanadium and cobalt, perhaps one of the best steels stainless steel cutlery, designed especially to cut.
Its main features:
- very high wear resistance.
- high edge retention.
- high resistance to corrosion.
- up to 63 HRC.
Chemical composition (%) : C:1. 08, si:0. 40, 40 Mn:0., Cr:17. 30, Mo:1. 10, v:0. 10, Co: 1.50
This steel is not recommended for beginners, its degree of difficulty of work is average.
Supplied annealed (soft), to facilitate the work, since tempered once is very difficult work.
- Forging: 900 to 1050 ° C. Warmup at 800 ° C for 20 to 25 minutes. Very slow cooling in furnace or insulation materials (sand, salt, mica).
- Normalizing : 800 to 850 ° C. To eliminate the structural tensions caused by forging or roughing. Preferred time, 1 hour.
- Hardening (to oil) : 1045 to 1080 ° C. Warmup at 950 ° C, stabilized temperature, thermal jump to temple, reached temperature, maintain at least 4 minute per millimeter . Cooling in oil to 180 - 200 ° C to reduce thermal shock, keep cool for 25 to 35 minutes. 61 to 63 HRC hardness.
- Tempering: double tempering. Slow heating up to the temperature of tempering (see temperature chart). The temperature reached 14 minutes per mm, the minimum recommended time is of 1 hour .
Quenching and tempering is recommended in atmosphere conservative, see tempered blade. This is the recommended thermal treatment, there are others. Temperatures, times or form of realization of it, depending on your needs you can vary or experience in such process.
MATERIAL cut by process mechanical, can be present CURVATURE (not flat).