KNIFE FOR METAL CUTTING Russian patent published in 2011 - IPC C22C38/24 

FIELD: metallurgy.

SUBSTANCE: knife is made out of alloyed steel containing carbon, silicon, manganese, chromium, tungsten, molybdenum, vanadium, sulphur, phosphorus and iron at the following ratio of components, wt %: carbon 0.57 - 0.67, silicon 0.70 - 1.00, manganese 0.40 - 0.70, chromium 2.70 - 3.20, tungsten 1.30 - 1.60, molybdenum 0.60 - 0.90, vanadium 0.50 - 0.90, sulphur not more, than 0.01, phosphorus not more, than 0.01, iron - the rest. Upon quenching from temperature 920°C and successive tempering at temperature 300°C steel has uniform structure wherein a grain has size 2-4 points, impact elasticity 29 J/cm² and hardness 56-58 HRC.

EFFECT: increased hardenability, mechanical properties and wear resistance under conditions of wear caused with high impact loads.

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