Cobalt based alloy product, method for manufacturing same, and cobalt based alloy article

A product formed of a cobalt based alloy, the cobalt based alloy having a chemical composition comprising:

• 0.08 to 0.25 mass % of carbon;
• 0.1 mass % or less of boron;
• 10 to 30 mass % of chromium;
• 5 mass % or less of iron, 30 mass % or less of nickel, the total amount of the iron and the nickel being 30 mass % or less;
• tungsten and/or molybdenum, the total amount of the tungsten and the molybdenum being 5 to 12 mass %;
• at least one of titanium, zirconium, hafnium, vanadium, niobium and tantalum, the total amount of the titanium, the zirconium, the hafnium, the vanadium, the niobium and the tantalum being 0.5 to 2 mass %;
• 0.5 mass % or less of silicon;
• 0.5 mass % or less of manganese;
• 0.003 to 0.04 mass % of nitrogen;
• and
• the balance being cobalt and impurities, the impurities including 0.5 mass % or less of aluminum, and 0.04 mass % or less of oxygen,
• wherein the product is a polycrystalline body of matrix phase crystal grains, and
• wherein in the polycrystalline body MC type carbide phase grains and M23C6 type carbide phase grains are co-precipitated, the MC type carbide phase grains being dispersively precipitated in the matrix phase crystal grains at an average intergrain distance of 0.13 to 2 μm, the M23C6 type carbide phase grains being precipitated on grain boundaries of the matrix phase crystal grains.