Method for producing a valve seat ring

A method for producing a valve seat ring, comprising:

• providing a first material composed of approximately 15 to 30% by weight of molybdenum, approximately 5 to 30% by weight of chromium, approximately 0 to 5% by weight of silicon, approximately 0 to 2% by weight of carbon, and up to 5% by weight of other elements and a remainder of cobalt, and a second material composed of approximately 10 to 12% by weight of chromium, approximately 0.5 to 0.8% manganese, approximately 0.5 to 1% by weight of silicon, approximately 0.5 to 0.9% by weight of carbon, up to approximately 3% by weight of other elements and a remainder of iron,
• processing the first materials and the second material to form a powder by atomising a metal melt so that the first material and the second material have a mean particle size of approximately 5 to 13 μm,
• processing the powder of each of the first material and the second material into a flowable granulate with a granulate size of substantially smaller than 300 μm and greater than 15 μm,
• admixing a proportion of 1 to 5% by weight of an organic pressing additive,
• filling the granulate of the first material and of the second material into a press tool one after the other and subsequently uniaxially pressing the granulate in the press tool with a pressing pressure of 400<p<700 MPa,
• removing the organic pressing additive by heating at a temperature 50° C.<t<700° C., and
• performing at least one of a pre-sintering and finish-sintering.