ASTM A240 304/304L Plates | Acetic Acid Corrosion Data

Acetic Acid: Properties & Applications

Acetic acid, CH₃COOH, also known as ethanoic acid or vinegar acid, is a clear, colorless liquid or crystalline mass with a pungent odor, a melting point of 16.7°C, and a boiling point of 118.1°C. It is miscible with water, alcohol, and ether, and it crystallizes in deliquescent needles. Acetic acid, as well as its derivatives, is produced in large quantities. It is the most important organic acid and is frequently encountered as a contaminant in other organic chemical processes. Acetic acid is classified as a weak acid, but the effective acidity in aqueous streams increases rapidly with concentration. In addition to being the active ingredient in vinegar, acetic acid is required in the production of synthetic resins and fibers, pharmaceuticals, photographic chemicals, flavorants, and bleaching and etching compounds. It is used as an active raw and intermediate material for various organic syntheses and as a solvent for organic substances.

Applications of 304/304L & Corrosion Data in Acetic Acids

Type 304 stainless steel finds wide application in dilute CH₃COOH and in the shipment and storage of concentrated CH₃COOH. It is the lowest grade commonly used in acetic acid industry. Compared to types 316 and 317, it is also more cost effective. Data show that glacial acetic acid can be handled in 304 stainless steel to a temperature of about 80°C [175°F] and that 304ss has been satisfactory for lower concentrations to the boiling point of the acid. At temperatures above 60°C [140°F], use of the low-carbon type 304L is advisable for welded construction to prevent intergranular attack of heat-affected zones. Various storage and transportation tanks for acetic acids at ambient temperatures are generally made from ASTM A240 TP304 or TP304L plates or sheets.

Concentration %	Temp. °C [°F]	Duration	Corrosion Rate mm/yr [mils/yr]
Concentrated	Boiling	-	0.081 [3.2]
10	Boiling	-	Resistant
60	15 [60]	-	Resistant
60	Boiling	-	Resistant
100	21 [70]	-	Resistant
100	Boiling	-	Good
20	-	-	7.5 [300]
10	20 [68]	-	Resistant
10	Boiling	-	Resistant
50	20 [68]	-	Resistant
50	Boiling	-	Good
100	20 [68]	-	Resistant
100	Boiling	-	Good
-	20 [68]	-	Resistant
-	Boiling	-	Resistant
5*A	21 [70]	-	Resistant
10*A	21 [70]	-	Resistant
83*B	116 [241]	51 days	1.68 [66]
87*B	122 [252]	51 days	1.07 [42]
98*B	128 [262]	51 days	0.18 [7.0]
20	boiling	24 hours	0.75 [30]
80	boiling	24 hours	-
30-50*C	106 [223]	-	poor
Concentrated*D	boiling	-	6.86 [270]
10*E	20 [68]	-	Resistant
10*E	50 [122]	-	Resistant
10*E	90 [194]	-	Resistant
50	boiling	48 hours	0.275 [11]

*Empirical corrosion behavior of type 304 in acetic acids in various concentration, temperatures, and other conditions.
*^A: Aearted. *^B: Data were obtained during processing of acetic acid containing ionized halogens; concentration of halide ions varied during period of observation; eliminated range of concentration, 5 to 10 ppm. *^C: plus 2~10% HCOOH. *^D: plus 220 ppm Cl^–. *^E: plus 50% hydrogen peroxide.

Concentration %	Temp. °C [°F]	Duration	Corrosion Rate mm/yr [mils/yr]
90	150 [302]	30 days	4.9 [193]
10	20 [68]	-	Resistant
10	Boiling	-	Resistant
50	20 [68]	-	Resistant
50	Boiling	-	Good
100	20 [68]	-	Resistant
100	Boiling	-	Good
-	20 [68]	-	Resistant
-	Boiling	-	Resistant
75*F	150 [302]	30 days	24.2 [953]
85*G	150 [302]	30 days	8.2 [323]
10*H	20 [68]	-	Resistant
10*H	50 [122]	-	Resistant
10*H	90 [194]	-	Resistant

*Empirical corrosion behavior of type 304L in acetic acids in various concentration, temperatures, and other conditions.
*^F: plus 15% formic acid. *^G: plus 5% formic acid. *^H:plus 50% hydrogen peroxide.

Chemical Composition of ASTM A240 TP304/TP304L

Element	TP304	TP304L
C	≤0.08	≤0.03
Mn	≤2.00	≤2.00
P	≤0.045	≤0.045
S	≤0.030	≤0.030
Si	≤0.75	≤0.75
Ni	8.0-11.0	8.0-12.0
Cr	18.0-20.0	18.0-20.0
N	≤0.10	≤0.10

*Base on both heat and product analysis.

Mechanical Properties of ASTM A240 TP304/TP304L

Mechanical Requirements	TP304	TP304L
Tensile Strength, min. MPa [ksi]	515 [75]	485 [70]
Yield Strength, min. MPa [ksi]	205 [30]	170 [25]
Elongation in 2" min. %	40	40
Brinell Hardness max. HBW	201	201
Rockwell Hardness Max. HRBW	92	92

*Charpy V-notch test may be performed upon client’s requirements.

Supply Chain & Cooperation

Shijiazhuang Metalsin holds large inventory of ASTM A240 TP304 & TP304L plates and sheets from several prominent steel mills in China including BAOSTEEL, TISCO, TSINGSHAN, and JISCO. Any inquiry, please feel free to contact our sales team at sales@pipingpipeline.com and info@pipingpipeline.com. For project bidding, we can act as your China local agent to coordinate with big steel mills.