Pre-weld heat treatment for nickel-base superalloys

摘要

Before welding a nickel-base superalloy comprising heating a nickel-base superalloy (eg, IN939) casting to 2120 ° F at a rate of 2 ° F per minute and soaking the casting at 2120 ° F for 1 hour. Heat treatment. The casting is then cooled, including slowly cooling to about 1900 ° F. at a rate of 1 ° F. per minute and maintaining at that temperature for about 10 minutes. The casting is then further slowly cooled to about 1800 ° F. at a rate of 1 ° F. per minute and maintained at that temperature for about 10 minutes, and further in a temperature range of 1650 ° F. to 1450 ° F. Cool slowly to room temperature and then cool rapidly to room temperature. The pre-weld heat treatment may optionally include heating the casting to about 1850 ° F. at a rate of 50 ° F. per minute and slowly heating to 2120 ° F.