Media	(%) Conc.	Test Temperature		Average Corrosion Rate Per Year, mils**
Media	(%) Conc.	°F	°(C)	C-22^® alloy	C-276 alloy	C-4 alloy	625 alloy

Acetic Acid	99	Boiling		Nil	<1	Nil	<1
Ferric Acid	10	Boiling		1	2	140	7325
Formic Acid	88	Boiling		<1	1	2	9

Hydrochloric Acid	1	Boiling		3	13	25	1
	1.5	Boiling		14	32	64	353
	2	194	(90)	Nil	1	31	Nil
	2	Boiling		61	51	82	557
	2.5	194	(90)	<1	12	34	72
	2.5	Boiling		141	85	44	605
	10	Boiling		400	288	228	642
Hydrochloric Acid + 42 g/l Fe₂(SO₄)₃	1	200	(93)	2	41	-	238
Hydrochloric Acid + 42 g/l Fe₂(SO₄)₃	5	150	(66)	2	5	3	2
Hydrochloric Acid + 2% HF	5	158	(70)	59	26	34	123
Hydrochloric Acid + 2% HF

Hydrofluoric Acid	2	158	(70)	9	9	17	20
	5	158	(70)	14	10	15	16

P₂O₅(Commercial Grade)	38	185	(85)	2	9	-	1
	44	240	(116)	21	100	-	23
	52	240	(116)	11	33	-	12
P₂O₅ + 2000ppm Cl	38	185	(85)	1	12	-	2
P₂O₅ + 2000ppm Cl
P₂O₅ + 0.5% HF	38	185	(85)	7	45	-	9

Nitric Acid	10	Boiling		<1	7	7	<1
	65	Boiling		134	888	217	21
Nitric Acid + 6% HF	5	140	(60)	67	207	204	73
Nitric Acid + 6% HF
Nitric Acid + 25% H₂SO₄ + 4% NaCl	5	Boiling		12	64	97	713
Nitric Acid + 25% H₂SO₄ + 4% NaCl
Nitric Acid + 1% HCl	5	Boiling		<1	8	11	1
Nitric Acid + 1% HCl
Nitric Acid + 2.5% HCl	5	Boiling		2	21	26	<1
Nitric Acid + 2.5% HCl
Nitric Acid + 15% HCl	8.8	126	(52)	4	33	114	>10,000

Sulfuric Acid	2	150	(66)	Nil	<1	Nil	Nil
	2	Boiling		5	6	6	6
	5	174	(79)	<1	1	1	<1
	5	Boiling		9	12	16	16
	10	Boiling		12	19	25	37
	20	150	(66)	<1	<1	<1	<1
	20	174	(79)	1	3	2	13
	20	Boiling		33	39	36	91
	30	150	(66)	<1	1	<1	<1
	30	174	(79)	3	4	3	27
	30	Boiling		64	55	73	227
	40	100	(38)	<1	<1	<1	<1
	40	150	(66)	<1	1	9	1
	40	174	(79)	9	10	15	35
	50	100	(38)	<1	Nil	<1	1
	50	150	(66)	1	4	13	25
	50	174	(79)	16	12	25	58
	60	100	(38)	<1	<1	1	<1
	70	100	(38)	Nil	Nil	2	<1
	80	100	(38)	Nil	<1	<1	<1

Sulfuric Acid + 0.1% HCl	5	Boiling		26	33	49	151
Sulfuric Acid + 0.5% HCl	5	Boiling		61	49	91	434
Sulfuric Acid + 1% HCl	10	158	(70)	<1	11	24	121
Sulfuric Acid + 1% HCl	10	194	(90)	94	45	66	326
Sulfuric Acid + 1% HCl	10	Boiling		225	116	192	869
Sulfuric Acid + 2% HF	10	Boiling		29	22	26	55
Sulfuric Acid + 200ppm Cl^-	25	158	(70)	11	12	37	110
Sulfuric Acid + 200ppm Cl^-	25	Boiling		215	186	182	325
Sulfuric Acid + 1.2% HCl + 1% FeCl₃ + 1% CuCl₂	11.5	Boiling		3	42	837	1815
Sulfuric Acid + 1.2% HCl + 1% FeCl₃ + 1% CuCl₂ (ASTMG28B)	23	Boiling		8	55	2155	2721
Sulfuric Acid + 1.2% HCl + 1% FeCl₃ + 1% CuCl₂ (ASTMG28A)	50	Boiling		40	250	143	23
Average of 4-10 tests. *To convert mils per year(mpy) to mm per year, divide by 40

Haynes International, Inc. 800-354-0806 765-456-6012

HASTELLOY® C-22® alloy Information*

HASTELLOY^® C-22^® alloy Information*