It is necessary to perform surface fine grain treatment on investment casting K417 Galloy low pressure turbine blade

however

excessive corrosion can be easily observed in the alloy during grain degree inspection.Effects of FeCl3

CuSO

4

corrosion agent on surface and properties of the K417 Galloy blade were analyzed.The results reveal that with CuSO

4

containing corrosion agent

carbide at grain boundary of the alloy can be flaked to lead to damage the grain boundary.Stress rupture testing at 950℃ and 235 MPa reveals that effects of corrosion on stress rupture of the alloy can be ignored for 5min

while it is deteriorated sharply for 20 min.With FeCl

3

containing corrosion agent

the flake of carbide at grain boundary of the alloy blade is absent.The stress rupture testing at 950 ℃ and 235 MPa reveals that effects of corrosion on stress rupture of the alloy blade can be ignored for 5min and 20 min

while it is decreased greatly for 40 min

which is attributed to the increase of shrinkage porosity in dendrite of the alloy with increasing in corrosion time.The FeCl

3

containing corrosion agent was adopted to inspect the grain degree of the turbine blade.