SA387Gr2CL2,SA387Gr12CL2,SA387Gr11CL2,SA387Gr22CL2,SA387Gr22LCL1,SA387Gr21CL2,SA387Gr21LCL1,SA387Gr5CL2,SA387Gr9CL2,SA387Gr91CL2,SA387Gr2CL1,SA387Gr12CL1,SA387Gr11CL1,SA387Gr22CL1,SA387Gr21CL1,SA387Gr5CL1,SA387Gr9CL1 | Pressure Vessel Plates Alloy Steel Chromium-Molybdenum ASTM A387/A387M-2023

1. Scope

1.1 This specification covers chromium-molybdenum alloy steel plates intended primarily for welded boilers and pressure vessels designed for elevated temperature service.

1.2 Plates are available under this specification in several grades having different alloy contents as follows:

Grade	Nominal Chromium Content, %	Nominal Molybdenum Content, %
2	0.50	0.50
12	1.00	0.50
11	1.25	0.50
22	2.25	1.00
21	3.00	1.00
5	5.00	0.50
9	9.00	1.00
91	9.00	1.00

1.3 Each grade except Grade 91 is available in two classes of tensile strength levels as defined in the Tensile Requirements tables. Grade 91 is available only as Class 2. Grade 91 consists of two types, with Type 2 differentiated from Type 1 by requiring restricted composition for the enhancement of creep resistance.

Note 1—Grade 911, previously covered by this specification, is now covered by Specification A1017/A1017M.

1.4 The maximum thickness of plates is limited only by the capacity of the composition to meet the specified mechanical property requirements.

1.5 The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents. Therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with this specification.

1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

2. Referenced Documents

2.1 ASTM Standards:

A20/A20M Specification for General Requirements for Steel Plates for Pressure Vessels
A370 Test Methods and Definitions for Mechanical Testing of Steel Products
A435/A435M Specification for Straight-Beam Ultrasonic Examination of Steel Plates
A577/A577M Specification for Ultrasonic Angle-Beam Examination of Steel Plates
A578/A578M Specification for Straight-Beam Ultrasonic Examination of Rolled Steel Plates for Special Applications
A1017/A1017M Specification for Pressure Vessel Plates, Alloy Steel, Chromium-Molybdenum-Tungsten

2.2 AWS Specifications:

A5.5/A5.5M Low-Alloy Steel Electrodes for Shielded Metal Arc Welding
A5.23/A5.23M Low-Alloy Steel Electrodes and Fluxes for Submerged Arc Welding
A5.28/A5.28M Low-Alloy Steel Electrodes and Rods for Gas Shielded Arc Welding
A5.29/A5.29M Low-Alloy Electrodes for Flux Cored Arc Welding

3. General Requirements and Ordering Information

3.1 Material supplied to this material specification shall conform to Specification A20/A20M. These requirements outline the testing and retesting methods and procedures, permissible variations in dimensions and weight, quality and repair of defects, marking, loading, and ordering information.

3.2 In addition to the basic requirements of this specification, certain supplementary requirements are available when additional control, testing, or examination is required to meet end use requirements. The purchaser is referred to the listed supplementary requirements in this specification and to the detailed requirements in Specification A20/A20M.

3.3 If the requirements of this specification are in conflict with the requirements of Specification A20/A20M, the requirements of this specification shall prevail.

4. Manufacture

4.1 Steelmaking Practice—The steel shall be killed.

5. Heat Treatment

5.1 Except for Grade 91, all plates shall be thermally treated either by annealing, normalizing and tempering, or, when permitted by the purchaser, accelerated cooling from the austenitizing temperature by air blasting or liquid quenching, followed by tempering. Minimum tempering temperatures shall be as follows:

Grade	Temperature, °F [°C]
2, 12, and 11	1150 (620)
22, 21, and 9	1250 (675)
5	1300 (705)

5.1.1 Grade 91 plates shall be thermally treated, either by normalizing and tempering or by accelerated cooling from the austenitizing temperature by air blasting or liquid quenching, followed by tempering. Grade 91 plates shall be austenitized at 1900 to 1975°F [1040 to 1080°C] and shall be tempered at 1350 to 1470°F [730 to 800°C].

5.2 Grade 5, 9, 21, 22, and 91 plates ordered without the heat treatment required by 5.1 shall be furnished in either the stress relieved or the annealed condition.

5.3 For plates ordered without the heat treatment required by 5.1, heat treatment of the plates to conform to 5.1 and to Table 2 or Table 3, as applicable, shall be the responsibility of the purchaser.

6. Chemical Requirements

6.1 The steel shall conform to the requirements as to chemical composition shown in Table 1 unless otherwise modified in accordance with Supplementary Requirement S17, Vacuum Carbon-Deoxidized Steel, in Specification A20/A20M for grades other than Grade 11.

TABLE 1 Chemical Requirements
Element	Composition, %
Element	Grade 2 S50460	Grade 12 K11757	Grade 11 K11789	Grade 22 K21590	Grade 21 K31545	Grade 5 S50200	Grade 9 K90941	Grade 91 Type 1 K90901	Grade 91 Type 2 K90901
Carbon: Heat analysis Product analysis	0.05–0.21 0.04–0.21	0.05–0.17 0.04–0.17	0.05–0.17 0.04–0.17	0.05–0.15^A 0.04–0.15^A	0.05–0.15^A 0.04–0.15^A	0.15 max 0.15 max	0.15 max 0.15 max	0.08–0.12 0.06–0.15	0.08–0.12 0.06–0.15
Manganese: Heat analysis Product analysis	0.55–0.80 0.50–0.88	0.40–0.65 0.35–0.73	0.40–0.65 0.35–0.73	0.30–0.60 0.25–0.66	0.30–0.60 0.25–0.66	0.30–0.60 0.25–0.66	0.30–0.60 0.25–0.66	0.30–0.60 0.25–0.66	0.30–0.50 0.30–0.50
Phosphorus, max: Heat analysis Product analysis	0.025 0.025	0.025 0.025	0.025 0.025	0.025 0.025	0.025 0.025	0.025 0.025	0.025 0.025	0.020 0.025	0.020 0.020
Sulfur, max: Heat analysis Product analysis	0.025 0.025	0.025 0.025	0.025 0.025	0.025 0.025	0.025 0.025	0.025 0.025	0.025 0.025	0.010 0.012	0.005 0.005
Silicon: Heat analysis Product analysis	0.15–0.40 0.13–0.45	0.15–0.40 0.13–0.45	0.50–0.80 0.44–0.86	0.50 max 0.50 max	0.50 max 0.50 max	0.50 max 0.55 max	1.00 max 1.05 max	0.20–0.50 0.18–0.56	0.20–0.40 0.20–0.40
Chromium: Heat analysis Product analysis	0.50–0.80 0.46–0.85	0.80–1.15 0.74–1.21	1.00–1.50 0.94–1.56	2.00–2.50 1.88–2.62	2.75–3.25 2.63–3.37	4.00–6.00 3.90–6.10	8.00–10.00 7.90–10.10	8.00–9.50 7.90–9.60	8.0–9.50 8.0–9.50
Molybdenum: Heat analysis Product analysis	0.45–0.60 0.40–0.65	0.45–0.60 0.40–0.65	0.45–0.65 0.40–0.70	0.90–1.10 0.85–1.15	0.90–1.10 0.85–1.15	0.45–0.65 0.40–0.70	0.90–1.10 0.85–1.15	0.85–1.05 0.80–1.10	0.85–1.05 0.80–1.05
Nickel, max: Heat analysis Product analysis	… …	… …	… …	… …	… …	… …	… …	0.40 0.43	0.20 0.20
Vanadium: Heat analysis Product analysis	… …	… …	… …	… …	… …	… …	0.04 max 0.05 max	0.18–0.25 0.16–0.27	0.18–0.25 0.16–0.27
Columbium (niobium):^A Heat analysis Product analysis	… …	… …	… …	… …	… …	… …	… …	0.06–0.10 0.05–0.11	0.06–0.10 0.05–0.11
Boron, max:^C Heat analysis	…	…	…	…	…	…	…	…	0.001
Nitrogen: Heat analysis Product analysis	… …	… …	… …	… …	… …	… …	… …	0.030–0.070 0.025–0.080	0.035–0.070 0.035–0.070
Nitrogen/Aluminum	…	…	…	…	…	…	…	…	≥4.0
Aluminum, max:^C Heat analysis	…	…	…	…	…	…	…	0.02	0.020
Titanium, max:^C Heat analysis	…	…	…	…	…	…	…	0.01	0.01
Zirconium, max:^C Heat analysis	…	…	…	…	…	…	…	0.01	0.01
Tungsten, max:^C Heat analysis	…	…	…	…	…	…	…	…	0.05
Copper, max:^C Heat analysis	…	…	…	…	…	…	…	…	0.10
Antimony, max:^C Heat analysis	…	…	…	…	…	…	…	…	0.003
Arsenic, max:^C Heat analysis	…	…	…	…	…	…	…	…	0.010
Tin, max:^C Heat analysis	…	…	…	…	…	…	…	…	0.010

^A The carbon content for plates over 5 in. [125 mm] in thickness is 0.17 max on product analysis.
^B Columbium and niobium are interchangeable names for the same element and both names are acceptable for use in A01 specifications.
^C Applies to both heat and product analysis.

7. Metallurgical Structure

7.1 Austenitic Grain Size—Grade 2 material shall have a coarse austenitic grain size.

8. Mechanical Requirements

8.1 Tension Test Requirements:

8.1.1 The material as represented by the tension test specimens shall conform to the applicable requirements of Table 2 or Table 3, as specified on the order.

8.1.2 Adjustment of the percentage elongation requirements is permitted in accordance with Specification A20/A20M for plates up to ¾ in. [200 mm] inclusive, in thickness when an 8-in. [200-mm] gauge length is used.

TABLE 2 Tensile Requirements for Class 1 Plates
	Grades 2 and 12	Grade 11	Grades 22, 21, 5, 9
Tensile strength, ksi [MPa]	55 to 80 [380 to 550]	60 to 85 [415 to 585]	60 to 85 [415 to 585]
Yield strength, min, ksi [MPa]	33 [230]	35 [240]	30 [205]
Elongation in 8 in. [200 mm], min, %^A	18	19	…
Elongation in 2 in. [50 mm], min, %^A	22	22	18
Reduction of area, min, %	…	…	45^B 40^C

^A See Specification A20/A20M, elongation adjustments.
^B Measured on round test specimens.
^C Measured on flat specimen.

TABLE 3 Tensile Requirements for Class 2 Plates^A
	Grade 2	Grade 11	Grade 12	Grades 22, 21, 5, 9	Grade 91
Tensile strength, ksi [MPa]	70 to 90 [485 to 620]	75 to 100 [515 to 690]	65 to 85 [450 to 585]	75 to 100 [515 to 690]	85 to 110 [585 to 760]
Yield strength, min, ksi [MPa]/0.2% offset	45 [310]	45 [310]	40 [275]	45 [310]	60 [415]
Elongation in 8 in. [200 mm], min, %^B	18	18	19	…	…
Elongation in 2 in. [50 mm], min, %^B	22	22	22	18	18
Reduction of area, min, %	…	…	…	45^C 40^D	…

^A Not applicable to annealed material.
^B See Specification A20/A20M, elongation adjustments.
^C Measured on round test specimens.
^D Measured on flat specimen.

9. Repair Welding

9.1 Repair welding shall be permitted only with the approval of the purchaser. Repair welds shall meet the requirements of the construction code specified by the purchaser.

9.2 All repair welds in Grade 91 shall be made with one of the following welding processes and consumables: SMAW, A5.5/A5.5M E90XX-B9; SAW, A5.23/A5.23M EB9 + neutral flux; GTAW, A5.28/A5.28M ER90S-B9; and FCAW A5.29/A5.29M E91T1-B9. In addition, the sum of the Ni+Mn content of all welding consumables used to weld repair Grade 91 plate shall not exceed 1.0%.

10. Marking

10.1 In addition to the marking required in Specification A20/A20M, each plate shall be legibly stamped or stenciled, depending upon the ordered thickness, with the letter A for annealed, N for normalized and tempered, and Q for accelerated cooled and tempered, as applicable. Grade 91 plates shall be marked with the appropriate type. Plates ordered to, and conforming to, Type 2 may be marked Type 1 as well.

11. Keywords

11.1 alloy steel; alloy steel plate; creep resistance; elevated temperature; pressure containing parts; pressure vessel steels; steel plates; steel plates for pressure vessels

SUPPLEMENTARY REQUIREMENTS

Supplementary requirements shall not apply unless specified in the order. A list of standardized supplementary requirements for use at the option of the purchaser is included in Specification A20/A20M. Several of those considered suitable for use with this specification are listed below by title. Other tests may be performed by agreement between the supplier and the purchaser.

S1. Vacuum Treatment,
S2. Product Analysis,
S3. Simulated Post-Weld Heat Treatment of Mechanical Test Coupons,
S4.1 Additional Tension Test,
S5. Charpy V-Notch Impact Test,
S6. Drop Weight Test (for Material 0.625 in. [16 mm] and over in Thickness),
S7. High-Temperature Tension Test,
S8. Ultrasonic Examination in accordance with Specification A435/A435M,
S9. Magnetic Particle Examination,
S11. Ultrasonic Examination in accordance with Specification A577/A577M,
S12. Ultrasonic Examination in accordance with Specification A578/A578M, and
S17. Vacuum Carbon-Deoxidized Steel.

FIG. S1.1 Transition Temperature Curves Before and After Step Cool Heat Treatment

ADDITIONAL SUPPLEMENTARY REQUIREMENTS

In addition, the following supplementary requirements are suitable for this application. S62 and S63 are applicable for Grades 22 and 21 only.

S53. Alternative Location for Mechanical Testing

When specified by the purchaser, the axis of the tensile and impact test specimens shall come from the mid-thickness of each plate tested, in lieu of midway between the center thickness and the top or bottom surface of the plate.

S60. Restricted Carbon

S60.1 The maximum carbon content of Grade 5 shall be 0.10%.

S62. Temper Embrittlement Factor

S62.1 The composition of the steel, based on heat analysis, shall be restricted in accordance with the following equations:

J = (Si+Mn) × (P+Sn) × 10⁴ ≤ 150 (Si, Mn, P and Sn in wt%)

Cu ≤ 0.20%

Ni ≤ 0.30%

S62.1.1 Lower values of J, Cu, and Ni can be specified by agreement between purchaser and the supplier.

S62.1.2 When so specified by the purchaser, the maximum value of J shall not exceed 100.

S62.1.3 The values of J shall be reported.

S62.1.4 If the plates are repaired by welding, the composition of the weld deposit shall be restricted in accordance with the following equations:

X = (10P + 5Sb + 4Sn + As)/100 ≤ 15 (P, Sb, Sn and As in ppm)

Cu ≤ 0.20%

Ni ≤ 0.30%

S62.1.5 The values of X shall be reported.

S63. Impact Properties After Step Cooling

S63.1 The Charpy V-notch impact properties shall be determined as follows:

S63.1.1 A sufficient amount of Charpy V-notch test specimens shall be taken from the same location from a plate from each heat of steel to construct two transition temperature curves.

S63.1.2 The test specimens for one transition temperature curve shall be given the minimum post weld heat treatment (PWHT) cycle specified by the purchaser.

S63.2 The test specimens for the other transition temperature curve shall be given the PWHT cycle specified in S63.1.2 plus the following step cooling heat treatment:

Hold at 1100°F (593°C) for 1 h, then cool at 10°F (5.6°C)/h to 1000°F (538°C).
Hold at 1000°F (538°C) for 15 h, then cool at 10°F (5.6°C)/h to 975°F (524°C).
Hold at 975°F (524°C) for 24 h, then cool at 10°F (5.6°C)/h to 925°F (496°C).
Hold at 925°F (496°C) for 60 h, then cool at 5°F (2.8°C)/h to 875°F (468°C).
Hold at 875°F (468°C) for 100 h, then cool at 50°F (27.8°C)/h to 600°F (315°C).
Cool in still air.

S63.3 Test the Charpy V-notch test specimens in accordance with Test Methods and Definitions A370 to determine the 40 ft-lbs (55 J) transition temperature from each transition temperature curve using a set of three test specimens at each test temperature. The test temperatures shall include tests on the upper and lower shelves and a minimum of four intermediate temperatures.

S63.4 The following requirements shall be met.

vTr40 + 2.5ΔvTr40 ≤ 50°F

vTr55 + 2.5ΔvTr55 ≤ 10°C

where:

vTr40 (vTr55) = the 40 ft-lbs (55 J) transition temperature of the material subjected to the minimum PWHT specified by the purchaser.

ΔvTr40 (ΔvTr55) = the shift of the 40 ft-lbs (55 J) transition temperature of the step cooled material. (The 40 ft-lbs (55 J) transition temperature of the step cooled material minus that of the material subjected to the minimum PWHT only).

S63.5 The 40 ft-lbs (55 J) transition temperatures for the two material conditions shall be reported.

SPECIFICATION FOR PRESSURE VESSEL PLATES, ALLOY STEEL, CHROMIUM-MOLYBDENUM