ASTM A541 Specification

Forgings, Fasteners, Boltings, Stud Bolts, Screws, Nuts

Scope

ASTM A541/ A541M Specification covers carbon steel & alloy steel forgings duly quenched and tempered for pressure vessel components. A541 Standard specification delegates thirteen different grades & five different classes of forgings used boilers, pressure vessels, and associated equipment applications.: The most commonly used forgings manufactured in accordance with ASTM A541 include tube sheets, hubbed flat heads, or nozzles, that are ordered for ASME Boiler and Pressure Vessel Code applications.

ASTM A541 Chemical Composition

Grade	C	M	P	S	Si	Ni	Cr	Mo	V	Ti	B	Cu	Nb	Ca
ASTM A541 Grade 1	0.35 max	0.40-0.90	0.025 max	0.025 max	0.15-0.35	0.40 max	0.25 max	0.10 max	0.05 max	. . .	. . .	. . .	. . .	. . .
ASTM A541 Grade 1A	0.30 max	0.70-1.35	0.025 max	0.025 max	0.15-0.40	0.40 max	0.25 max	0.10 max	0.05 max	. . .	. . .	. . .	. . .	. . .
ASTM A541 Grade 2	0.27 max	0.50-0.90	0.025 max	0.025 max	0.15-0.35	0.50-1.00	0.25-0.45	0.55-0.70	0.05 max	. . .	. . .	. . .	. . .	. . .
ASTM A541 Grade 3	0.25 max	1.20-1.50	0.025 max	0.025 max	0.15-0.35	0.40-1.00	0.25 max	0.45-0.60	0.05 max	. . .	. . .	. . .	. . .	. . .
ASTM A541 Grade 1C	0.18 max	1.30 max	0.025 max	0.025 max	0.15-0.35	0.25 max	0.15 max	0.05 max	0.02-0.12	. . .	. . .	. . .	. . .	. . .
ASTM A541 Grade 11 Class 4	0.10-0.20	0.30-0.80	0.025 max	0.025 max	0.50-1.00	0.50 max	1.00-1.50	0.45-0.65	0.05 max	. . .	. . .	. . .	. . .	. . .
ASTM A541 Grade 22 Classes 4 and 5	0.05-0.15	0.30-0.60	0.025 max	0.025 max	0.50 max	0.50 max	2.00-2.50	0.90-1.10	0.05 max	. . .	. . .	. . .	. . .	. . .
ASTM A541 Grade 4N	0.23 max	0.20-0.40	0.025 max	0.025 max	0.30 max	2.8-3.9	1.25-2.00	0.40-0.60	0.03 max	. . .	. . .	. . .	. . .	. . .
ASTM A541 Grade 5	0.23 max	0.20-0.40	0.025 max	0.025 max	0.30 max	2.8-3.9	1.25-2.00	0.40-0.60	0.08 max	. . .	. . .	. . .	. . .	. . .
ASTM A541 Grade 3V	0.10-0.15	0.30-0.60	0.020 max	0.020 max	0.10 max	. . .	2.8-3.3	0.90-1.10	0.20-0.30	0.015-0.035	0.001-0.003	. . .	. . .	. . .
ASTM A541 Grade 22 Class 3	0.11-0.15	0.30-0.60	0.015 max	0.015 max	0.50 max	0.25 max	2.00-2.50	0.90-1.10	0.02 max	. . .	. . .	. . .	. . .	. . .
ASTM A541 Grade 22V	0.11-0.15	0.30-0.60	0.015 max	0.010 max	0.10 max	0.25 max	2.00-2.50	0.90-1.10	0.25-0.35	0.030 max	0.0020 max	0.20 max	0.07 max	0.015 max2
ASTM A541 Grade 3VCb	0.10-0.15	0.30-0.60	0.020 max	0.010 max	0.10 max	0.25 max	2.7-3.3	0.90-1.10	0.20-0.30	0.015 max	. . .	0.25 max	0.015-0.070	0.0005-0.0150

ASTM A541 Mechanical Requirements

Grade	in. [mm], max
1 and 1A	3 [75]
2 Class 2 and 3 Class 2	6 [150]
2 Class 1 and 3 Class 1	8 [205]
1C	4 [100]
11 Class 4	5 [125]
22 Class 4, 4N Class 2, 5 Class 2	6 [150]
22 Class 5	8 [205]
4N Class 1, 5 Class 1, 4N Class 3, 3V, 3VCb, 22V, and 22 Class 3	10 [255]

ASTM A541 Tensile Requirements

Grade	Tensile strength, ksi [MPa]	Yield strength (0.2% offset), min, ksi [MPa]	Elongation in 2 in. or 50 mm, min, %	Reduction of area, min, %
Grades 1 and 1A	70 to 95 [485–660]	36 [250]	20	38
Grades 2 Class 1, 3 Class 1, 1C and 11 Class 4	80 to 105 [550–720]	50 [340]	18	38
Grade 2 Class 2 and Grade 3 Class 2	90 to 115 [620–790]	65 [450]	16	35
Grade 22 Class 4	105–130 [720–900]	85 [590]	16	45
Grade 22 Class 5	115–140 [790–1000]	100 [690]	15	40
Grade 4N Class 1 and Grade 5 Class 1	105 to 130 [720–900]	85 [590]	18	48
Grades 4N Class 2 and 5 Class 2	115–140 [790–1000]	100 [690]	16	45
Grade 4N Class 3	90 to 115 [620–790]	70 [480]	20	48
Grades 3V and 22V	85–110 [585–760]	60 [415]	18	45
Grade 22 Class 3	85–110 [585–760]	55 [380]	18	45
Grade 3VCb	85–110 [585–760]	60 [415]	18	45

ASTM A541 V-Notch Impact Requirements

Grade	Minimum average value of set of three specimens, ft·lbf (J)3	Minimum value of one specimen, ft·lbf (J)
Grades 1, 1A, and 11 Class 4	15 [20]	10 [14]
Grade 2 Class 2 and 3 Class 2	35 [47]4	30 [41]4
Grade 2 Class 1, 3 Class 1 and 1C	30 [41]	25 [34]
Grade 22 Class 5	25 [34]	20 [27]
Grades 22 CL 4 4N Classes 1, 2, 3, 2005 Classes 1,2	35 [47]	30 [41]
Grades 3V and 3VCb, Grade 22, Class 3 and Grade 22V	40 [55]5	35 [50]5

ASTM A541 Heat Treatment

After complete austenization, the forgings shall be quenched in a suitable liquid medium by spraying or immersion. For Grade 22V forgings, the minimum austenitizing temperature shall be 1650°F [900°C]. Quenching shall be followed by tempering at a subcritical temperature and holding at this temperature for a minimum time of ¹⁄₂ h/in. [25 mm] of maximum section thickness. Minimum tempering temperatures shall be:

Grade	°F [°C]
1, 1A, 2 Class 2, 3 Class 2	1150 [620]
2, 3, Class 2, 22 Class 3	1200 [650]
1C, 11 Class 4, 22 Class 4, 4N Class 1, 4N Class 2, 5 Class 1, 5 Class 2	1100 [595]
22 Class 15	1050 [565]
4N Class 3	1125 [610]
3V	1250 [675]
22V	1250 [675]

For Classes 1, 1A, 2, 2A, 3, or 3A a multiple stage austenitizing procedure may be used whereby the forging is first fully austenitized and liquid quenched, followed by reheating within the intercritical tempera- ture range to partially reaustenitize, and again liquid quenched. On completion of the austenitizing/quenching cycles, the forgings shall be tempered at a subcritical temperature

ASTM A541 Surface Treatment Specifications

ASTM A541 Components Marking

The purchaser may specify additional identifica- tion marking and the location of the marking. If stamps are used, they shall be round-nosed or “interrupteddot” die stamps having a minimum radius of ¹⁄₃₂ [.8 mm].

ASTM A541 Supplementary Requirements