Fatigue Strength Evaluation for Remanufacturing Impeller of Centrifugal Compressor Based on Modified Grey Relational Model

Table 3

Parameter of working condition, transmission mode, and material property of the reference impeller.

Parameter name		No. 0	No. 1	No. 2	No. 3	No. 4	No. 5
Input speed	n0 (r/min)	8877	22500	6667	5035	11200	8200
Inlet pressure	Pin (kg/cm^2)	1.02	1.025	1.1005	0.955	1.008	1.048
Inlet temperature	tin (°C)	27	21	30	37	29	32
Outlet pressure	Pout (kg/cm^2)	1.78	2.954	3.533	3.793	2.223	1.898
Lubrication condition	L	1	1	1	1	1	1
Wear degree	W	0	1	0	0	0	1
Cleanness of fluid	C	1	1	2	3	3	2
Position of impeller	N	1	1	1	1	1	1
Impeller form	N	1	1	2	1	1	1
Blade form	F	2	2	2	3	2	3
Rotor form	WR	1	1	1	3	1	2
Stress ratio	R	0.82	0.72	0.85	0.77	0.81	0.79
Material	M	FV520B-I	FV520B-I	X12Cr13-I	KMN-I	FV520B-S	FV520B-S
Tensile strength		1078	1078	735	931	931	887
Vickers hardness	HV	370	370	280	320	320	300
Fatigue strength value	S (MPa)	—	662	445	529	476	579