Method for preparing a nickel-based alloy

A method for the manufacture of a nickel-base alloy, in which

• an electrode is generated by VIM,
• if the Ni-base alloy forms a gamma prime phase:
• the electrode is introduced into a furnace before the electrode becomes cooler than 200° C.,
• for reduction of stresses and for over-aging, the electrode is subjected in a furnace to a heat treatment in the temperature range between 500 and 1250° C. for a period of 10 to 336 hours,
• the electrode is cooled in air or in the furnace to a temperature between room temperature and lower than 900° C.,
• the surface of the electrode is machined for removal of defects and is cleaned,
• the cooled electrode is then remelted by ESR at a remelting rate of 3.0 to 10 kg/minute to obtain an ESR ingot with a diameter of 400 to 1500 mm,
• the ESR ingot is cooled in air or in the furnace to a temperature between room temperature and lower than 900° C.,
• if necessary, the surface of the ESR ingot is machined for removal of defects and is cleaned,
• the cooled ESR ingot is subjected to a further heat treatment in the temperature range between 500 and 1250° C. for a period of 10 to 336 hours;
• the ESR ingot is cooled in air or in the furnace to a temperature between room temperature and lower than 870° C.,
• the ESR ingot is remelted again by means of VAR at a remelting rate of 3.0 to 10 kg/minute and a range of fluctuation of the remelting rate of smaller than 15% to obtain a VAR ingot with a diameter of 400 to 1500 mm,
• if the Ni-base alloy forms a gamma prime phase:
• the VAR ingot is introduced into a furnace before it the VAR ingot becomes cooler than 200° C. in the top region,
• the remelted VAR ingot is subjected to a heat treatment in the temperature range between 500 and 1250° C. for a period of 10 to 336 hours,
• the VAR ingot is cooled in air or in the furnace to a temperature between room temperature and lower than 900° C., or while still hotter than 850° C. is delivered to a hot-working process, and
• the VAR ingot is then brought by hot and/or cold working to the desired product shape and dimension.