公开(公告)号：CA1299070C

公开(公告)日：1992-04-21

申请号：CA539121

申请日：1987-06-08

Applicant: UNITED TECHNOLOGIES CORP

Inventor： HENRICKS ROBERT J ,  MARCIN JOHN J ,  WAHL JACQUELINE B ,  PINKOWISH ALEXANDER A

IPC: C22F1/10 ,  C22F1/00 ,  C23F1/00 ,  C30B33/00 ,  F01D5/28 ,  F02C3/06 ,  C30B29/52

Abstract: Stress Relief of Single Crystal Superalloy Articles A coated nickel base superalloy single crystal turbine airfoil blade (1), which is subject to gas turbine engine operation, can crack during refurbishment by a stress corrosion mechanism when exposed to certain corrosive media. The rapid thermal cycling that occurs during typical gas turbine engine operation results in high, non-uniform stresses across the airfoil, producing large localized residual strains in the article at ambient temperatures. Exposure to a corrosive environment, such as during coating removal or agressive cleaning, can produce chordwise cracks in a large number of the airfoils exposed. Such cracking is avoided by subjecting the articles to a preliminary stress relieving heat treatment which reduces the residual strains to a level below which cracking will not occur, prior to exposure to the corrosive media.