HAYNES ® 188 alloy - Haynes International, Inc.

THERMAL STABILITYHAYNES® 188 alloy is similar tothe solid-solution-strengthenedsuperalloys, such as alloy 625or HASTELLOY® X alloy, whichwill precipitate deleteriousphases upon such long termexposure. In this case, thephase in question is a C02Wlaves phase, which serves toimpair both tensile ductility andimpact strength. The behaviorof 188 alloy is significantly better in this regard than HAYNES25 alloy, which it replaced; butfor applications where thermalstability is important, 230° alloyis recommended.EXPOSURE TEMPERATURE (°C)AT 500 600 700 800 900 1000I I I I I I2 ~ . Retained Room-TemperatureTensile Ductility after 8000zHour Exposure at Temperature9uJ5f3Ui-jE5zUi40 -~D200-2LiiI- 1020RT 1000 1200 1400 1600 1800ExPOSURE TEMPERATURE (°F)ROOM-TEMPERATURE PROPERTIES OF PLATE AFTER THERMAL EXPOSUREUltimateExposureTensile0.2% Yield Elongation ImpactTemperatureStrengthStrength in 2 in. (51 mm) Strength°F (°C)Hours Ksi MPa Ksi MPa % Ft-lbs. Joules1200 0 140.0 965 65.0 450 56.0 143 194(650C) 8000 151.6 1045 79.7 550 29.1 23 311400 0 140.0 965 65.0 450 56.0 143 194(7600) 8000 147.9 1020 74.0 510 10.8 3 41600 0* 146.0 1005 70.1 485 50.4 143 194(8700) 1000 157.5 1085 70.7 490 28.7 10 134000 156.0 1075 68.8 475 26.6 10 138000* 147.4 1015 64.5 445 22.2 9 1216000 146.1 1005 63.8 440 24.0 8 11Average of two test exposures. All others single exposures.COMPARATIVE IMPACTSENOTH AFTER 8000-HOUR EXPOSURESSolution-AnnealedCharpy V-Notch ImpactCharpy V-Notch Impact Following ExposureFor 8000 Hours at Temperatures, Ft-lbs. (Joules)Material Ft.-lbs. (Joules) 1200°F (650°C) 1400°F (760°C) 1600°F (870°C)230® alloy 54 (73) 30 (41) 21 (28) 21 (28)188 a byXalIoy 54 (73) 15 (20) 8 (11) 15 (20)625 alloy 81 (110) 5 (7) 5 (7) 15 (2’)7 HAYNES 188 aloy