2007 SECTION II, PART ASA-372/SA-372M SPECIFICATION FOR CARBON AND ALLOY STEEL FORGINGS FOR THIN-WALLED PRESSURE VESSELS SA-372/SA-372M (Identical with ASTM Specification A 372/A 372M-95, except for a new para. 4.3.1 on the timing of heat treatment and renumbering of the existing paras. 4.3.1 through 4.3.4.) 1. Scope 1.1 This specification covers relatively thin-walled forgings (including gas bottles) for pressure vessel use. Three types of carbon steel and six types of alloy steel are included. Provision is made for integrally forging the ends of vessel bodies made from seamless pipe or tubing. therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the specification. 1.3 Unless the order specifies the applicable “M” specification designation (SI units), the material shall be furnished to inch-pound units. NOTE 1 — When working to the chemical and tensile requirements of this specification, the influence of wall thickness and cooling rate will necessarily eliminate certain forging sizes in each class. 2. Referenced Documents 2.1 ASTM Standards: A 275/A 275M Test Method for Magnetic Particle Examination of Steel Forgings A 370 Test Methods and Definitions for Mechanical Testing of Steel Products A 388/A 388M Practice for Ultrasonic Examination of Heavy Steel Forgings A 530/A 530M Specification for General Requirements for Specialized Carbon and Alloy Steel Pipe A 788 Specification for Steel Forgings, General Requirements E 112 Test Methods for Determining the Average Grain Size E 165 Practice for Liquid Penetrant Examination E 290 Test Method for Semi-Guided Bend Test for Ductility of Metallic Materials E 433 Referenced Photographs for Liquid Penetrant Inspection NOTE 2 — Designations have been changed as follows: Current Grade Grade Grade Grade Grade Grade Grade Grade Grade Grade Grade Grade Grade Grade Grade Grade Grade Grade Grade Grade Grade Grade Grade Grade A B C D E Class 55 E Class 65 E Class 70 F Class 55 F Class 65 F Class 70 G Class 55 G Class 65 G Class 70 H Class 55 H Class 65 H Class 70 J Class 55 J Class 65 J Class 70 K L J Class 110 M Class A M Class B Formerly Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type Type I II III IV V Grade 1 Class V Grade 1 Class V Grade 1 Class V Grade 2 Class V Grade 2 Class V Grade 2 Class V Grade 3 Class V Grade 3 Class V Grade 3 Class V Grade 4 Class V Grade 4 Class V Grade 4 Class V Grade 5 Class V Grade 5 Class V Grade 5 Class VI VII VIII IX Class A IX Class B 55 65 70 55 65 70 55 65 70 55 65 70 55 65 70 3. Ordering Information and General Requirements 3.1 In addition to the ordering information required by Specification A 788, the purchaser shall include with the inquiry and order a detailed drawing, sketch, or written description of the forging and the areas of significant loading in the forging when required (see 6.4.2.2). 1.2 The values stated in either inch-pound or SI [metric] units are to regarded separately as the standard. Within the text and the tables, the SI units are shown in brackets. The values stated in each system are not exact equivalents; 701 Copyright ASME International Provided by IHS under license with ASME No reproduction or networking permitted without license from IHS Licensee=Occidental Chemical Corp New sub account/5910419101 Not for Resale, 08/13/2007 15:19:31 MDT and additional supplementary requirements. and Class 110 of Grade J forgings shall be liquid-quenched and tempered.3. a flattening test is required.2 Tension Test — When tested in accordance with Test Methods and Definitions A 370. This does not preclude use of deoxidation or inclusion control additions. 4. particularly hydrogen.2 Material supplied to this specification shall conform to the requirements of Specification A 788.1 Mechanical tests for acceptance shall be made after the final heat treatment of the forgings.SA-372/SA-372M 2007 SECTION II. the requirements of this specification shall prevail.3.2 At the option of the manufacturer.2 Product Analysis — The purchaser may use the product analysis provision of Specification A 788 to obtain a product analysis from a forging representing each heat or multiple heat.1 Cold drawing or cold working operations shall be completed before any heat treatment that is done for the enhancement of mechanical properties.4. certification.1 Heat Analysis —The heat analysis obtained from sampling in accordance with Specification A 788 shall comply with Table 1. [25 mm] of maximum cross section. swedging. normalized and tempered. 5. Chemical Composition 5. 3. which outlines additional ordering information. 5. [355 mm]. H.2% offset method. Grades A.0 or less at the manufacturer’s option.3. the piercing of billets or plates.3 If the requirements of this specification are in conflict with the requirements of Specification A 788. J in Classes 55. in order to remove objectionable gases. In all cases there shall be sufficient discard to ensure soundness in the completed forging. 702 Copyright ASME International Provided by IHS under license with ASME No reproduction or networking permitted without license from IHS Licensee=Occidental Chemical Corp New sub account/5910419101 Not for Resale. 4. or pressing.3. The bend test pin diameter shall be as specified in Table 4. and the wall thickness.3 Grades K. or liquid-quenched and tempered.1 For bored or hollow forgings with outside diameters of 14 in. F. G. No breaks or cracks in the test ring are acceptable until the distance between the plates is less than that shown in Table 3. 6. 6. or a transverse bend test in accordance with Arrangement C of Test Method E 290 is required. This shall be carried out in accordance with Specification A 530/A 530M and Table 3.3 Heat Treatment: 4. [355 mm] or less and with a D/T ratio of more than 10. 6.4 When normalized forgings are to be tempered. PART A 3. testing and retesting methods and procedures.1 Melting Practice: 5. or when forgings have been quenched. B. 4. marking. L. 4. and the subsequent drawing of cups so produced. a bend test or flattening test will be required. Materials and Manufacture 4.1. [595°C] [540°C] [540°C] [595°C] 4.2 For bored or hollow forgings with outside diameters 14 in.3 Bending Properties —Depending upon the outside diameter. only steel that has been vacuum treated prior to or during the pouring of the ingot. they shall be reheated to a subcritical temperature and held for at least 1 ⁄2 h/in. No cracks or ruptures in the test piece are allowable when the test piece is bent through the required angle.3. product analysis variations. the flattening test specified in 6. of hollow or bored forgings. 6. 4. the material shall conform to the requirements of Table 2. 70 of Grades E. shall be used.0. 4. C.1. 08/13/2007 15:19:31 MDT .2. 4.1 The steel melting procedures of Specification A 788 shall apply except that for Grade M forgings.3. The yield strength shall be determined by the 0. T. 4. or where the D/T ratio is 10. H. 65. D and Classes 55. Such semi-finished forgings or seamless steel pipe or tubing may be closed by spinning. manufacturing requirements.1 Minimum tempering temperatures shall be as follows: Grades E.3.3.3. 6.5 All quenched and tempered forgings shall be subject to magnetic particle examination in accordance with Section 7. D. and J forgings shall be normalized. M.1 Methods for the production of gas bottles and similar vessels may include the cupping of slabs or plates. F. G. 70 Grade K Grade L Grade J Class 110 Grade M 1100°F [595°C] 1100°F 1000°F 1000°F 1100°F Mechanical Properties 6. 65.3 Starting material produced to a specification that specifically requires the addition of any element beyond those listed in Table 1 for the applicable grade of material is not permitted. Supplementary Requirements S1 and S2 of Specification A 788 shall apply.2 Production Methods: 4. 3 For heat-treated forgings weighing 1000 lb [450 kg] or more. in any continuous period up to 4 h duration in accordance with 6. taken in accordance with 6.2) shall be subject to a uniformity check by Brinell hardness testing.1 All quenched and tempered forgings shall be subject to magnetic particle examination after heat treatment. In addition. Magnetic Particle Examination 7. each with a heattreated weight of less than 1000 lb [510 kg] when heat treated in a single batch furnace charge.1 Test specimens representing vessel bodies or shells shall be located at a position corresponding to the mid-wall location of the parallel side wall of the heattreated forging and shall be oriented parallel to the longitudinal axis of the vessel.5.4. from a representative forging. the remainder of that production group shall be hardness tested and all of those forgings that fall outside these limits shall be retempered or reheat-treated at the manufacturer’s option and retested. The methods used shall be in accordance with Test Method A 275/A 275M.3. or an equivalent method. 6. for hollow or bored forgings. weighing less than 1000 lb [450 kg] each when heat treated in a continuous furnace.2 When forgings are contour-machined prior to heat treatment so that highly stressed surfaces are exposed. provided that such irregularity will not 703 Copyright ASME International Provided by IHS under license with ASME No reproduction or networking permitted without license from IHS SA-372/SA-372M Licensee=Occidental Chemical Corp New sub account/5910419101 Not for Resale. The length of test rings that will be liquid quenched must be at least 24 in. or from an integral prolongation when the part is contourmachined prior to heat treatment. [40 mm] or 2t. from test rings that have been heat treated with the forgings they represent.2 Test specimens representing vessel covers or similar components may be taken from a full section prolongation of the cover. 6. The ends of such test rings may be vented to prevent pressure buildup during heat treating.6 Hardness Testing: 6.4. In addition.5. one bend or flattening test shall be taken in accordance with 6.1. but not less than 3⁄4 in. to represent each ten or fewer forgings for the same heat and heat-treatment lot. one tension test shall be taken in accordance with 6. In addition. 6. then the test ring must have its ends closed. or from a representative forging after heat treatment in accordance with 4.2007 SECTION II. 6.1.2 Only direct current or rectified alternating (full or half wave) current shall be used as the electric power source for any of the magnetizing methods.4. they may be inspected for Type II indications referenced in Reference Photographs E 433 when inspected by the liquid penetrant method in accordance with Practice E 165.1 or 6.2 In the event that the test sample does not meet these criteria. 6.5. 7.3. the test specimens may be taken at an equal distance (t) from the nearest quenched surface as the highly stressed area. the test ring shall be from the same heat of steel and be subjected to the same heat treatment as the cylinders it represents.4. 6. In addition.2 Like forgings.2. the forgings may be accepted by the purchaser.1) or in a continuous furnace run covering up to 200 pieces in up to four hours production (6.1 Forgings under 1000 lb [450 kgm] in weight.3.1 Up to 200 like forgings.5. bored or hollow forgings shall have one bend or flattening test taken per heat per 200 forgings 8. For this purpose. hollow or bored forgings shall have one bend or flattening test.4.4. 6. if the cylinders are quenched from the outside only.3.3. heat treated in a batch lot of up to 200 pieces (6. shall have one tension test taken in accordance with 6. In case of doubt as to the type of condition giving rise to linear magnetic particle indications.2 to represent each heat.1 Test specimens representing vessel bodies or shells shall be taken from a prolongation of a forging.5 Number of Tests: 6. 7. 6. The method of quenching the test ring must duplicate that of the cylinders. 6.5. PART A 6.2 A test ring shall be in the shape of a right circular cylinder having the same diameter and wall thickness as the cylinders it represents.6. shall have one tensile test taken to represent each heat and not more than 200 forgings in any continuous period up to 4 h duration.4.4 Orientation and Location of Test Specimens: 6. some other suitable method for classifying the indications may be used as agreed upon between the manufacturer and the purchaser. [20 mm].3 The forgings shall be free from linear indications indicative of cracks.1 Test specimens taken from full size prolongations or representative forgings shall be located at a position midway between the center and the surface.4.6. Alternatively. The location of the specimens from a second surface shall be at least the greater of 11⁄2 in.2 to represent each heat and not more than ten forgings in a heat-treat lot.4. 08/13/2007 15:19:31 MDT .1 If the thickness of a portion of the wall of a forging is less than that specified. Workmanship 8.4. 10% of the furnace production shall be sampled and shall meet the minimum hardness specified in Table 2 for the type and shall also be within 20 Brinell points of the hardness of the forging from which the tensile test was taken. [610 mm]. 6.1 or 6. 7.2. .. max Sulfur.`. 65. . thin wall Repair Welding 9.`. 70 Grade J Classes 55.08 max 704 Licensee=Occidental Chemical Corp New sub account/5910419101 Not for Resale.00 0.40–0.25 0..80 0. 70 Grade H Classes 55. 0... 0.```.35 .1 alloy steel forgings...25 Grade K Grade L 0.40–0. 0.15–0.65 0. .35 2.15–0.80 0..15–0..`.020 0.....65 0.40 0.90 0.15–0.23 max 0. max Silicon Nickel Chromium Molybdenum Carbon Manganese Phosphorus..9 1.``.50–2. and shall be performed in accordance with all the requirements of the applicable code or rules of construction.35 .10–0.35 . max Silicon Nickel Chromium Molybdenum Vanadium --``.18 max 0..```..48 max 1.025 0.15–0..40–0..15–0.05 0.25–0.35 0.025 0.35–0.15–0...20–0. .40 0. 0.025 0.025 0.`.25 0.-`-`.05 0.15–0...15 0.025 0.17–0.30 . % Elements Grade A Grade B Grade C Grade D Carbon Manganese Phosphorus.00 0.15–0.40–1.50 1.27 Carbon Manganese Phosphorus. max Silicon Nickel Chromium Molybdenum 0.025 0..40–0...025 0. 65.25 0.35 .60 .15 0.15–0.70–1.. 65.025 0. 65.60–0.20–0.35 max 0.60 0.``. pressure vessels. .15–0.25 0...35 max 1.025 0.15–0..15–0.50 0.80–1.15 0.025 0.75–1.80–1. .025 0.15–0. PART A require lowering the allowable working pressure below that for which the forging was designed..025 0.`.80 0. gas bottles. Keywords 10. 0.35 .30 max 1.025 0.025 0.40 0.35 ..75–1.025 0.70–0.20–0.020 0... 10.025 0. 9.40 0.`.1 Repair welding shall be permitted when mutually agreed upon between the purchaser and the manufacturer TABLE 1 CHEMICAL REQUIREMENTS Composition..70–1.00–1. 0. max Sulfur.. 65.35 0. ..65–2.25–0.15–0.43 0..30–0.00 0.025 max 0.30–0. 08/13/2007 15:19:31 MDT . 70.40–0.025 0.65 max 0.30 max 2. carbon steel forgings.3 1.35 1..35 .35 ..00 max 0. 0.90 0.15–0.8–3..00 0.SA-372/SA-372M 2007 SECTION II..025 0.80–1. 0.025 max 0. max Sulfur.025 0. 110 0. 0. 0.0–3..38–0.`--- Copyright ASME International Provided by IHS under license with ASME No reproduction or networking permitted without license from IHS Grade E Classes 55.`.. 70 Grade F Classes 55. 70 Grade G Classes 55. Grade M Classes A and B 0.025 0..35 . G.8 0.`.```.9 0. min.`. min A [415–585] [515–690] [620–795] [725–895] [545–760] 35 [240] 45 [310] 55 [380] 65 [450] 55 [380] 20 18 15 15 20 121 156 187 217 179 105–130 [725–895] 65 [450] 19 217 120–145 [825–1000] 70 [485] 18 248 110 [760] 80 [550] 135 [930] 85 [585] 100 [690] 15 20 12 18 16 277 207 311 217 248 135–160 100–125 155–180 105–130 120–145 [930–1100] [690–860] [1070–1240] [725–895] [825–1000] When required by 6. H. G.`. H. min 60–85 75–100 90–115 105–130 85–110 Hardness. F.```. 705 Copyright ASME International Provided by IHS under license with ASME No reproduction or networking permitted without license from IHS Licensee=Occidental Chemical Corp New sub account/5910419101 Not for Resale.2007 SECTION II.. J (Class 70) Grade J (Class 110) Grade K Grade L Grade M (Class A) Grade M (Class B) A Yield Strength (0.`. F.65 0. J (Class 55) Grades E. J (Class 65) Grades E.. F. F. J (Class 70) Grade J (Class 110) Grade K Grade L Grade M (Class A) Grade M (Class B) A Elongation in 2 in. J (Class 55) Grades E.``. H. ksi [MPa] Type Grade A Grade B Grade C Grade D Grades E. TABLE 4 MAXIMUM PIN DIAMETERS AND MINIMUM ANGLE FOR BEND TEST TABLE 3 DISTANCE BETWEEN PLATES FOR FLATTENING TESTS A Type --``. G. PART A SA-372/SA-372M TABLE 2 MECHANICAL REQUIREMENTS Tensile Strength. F. % Distance Between Plates. min..`.`.. G.``..7 0. F.6.9 0.8 D D D D D D D D D D D D Type Pin Diameter Angle. in. G.7 0. ksi [MPa].7 0. J (Class 65) Grades E.. H. H.8 0. G. H. J (Class 65) Grades E. F. [50 mm].`. H. G.2% Offset).8 0. G.6 0. H. H. F. J (Class 55) Grades E. 08/13/2007 15:19:31 MDT . G.50 0. J (Class 70) Grade J (Class 110) Grade K Grade L Grade M (Class A) Grade M (Class B) 2t 2t 3t 4t 4t 4t 4t 6t 4t 6t 4t 4t 180 180 180 150 150 150 150 150 150 150 150 150 D p outside diameter.-`-`. [mm] 0.. deg Grade A Grade B Grade C Grade D Grades E. F.`--- Grade A Grade B Grade C Grade D Grades E. HB. 1 Charpy V-notch test specimens shall be taken from the same location and in the same orientation as tension test specimens.`. Forgings in the permitted types shall comply with the applicable Code sections..1 When a grain size range is required.```. 706 Copyright ASME International Provided by IHS under license with ASME No reproduction or networking permitted without license from IHS Fracture Toughness --``.. it shall be specified in the ordering information and shall be determined by an agreed-upon method for Test Methods E 112. or order.`.`--- Licensee=Occidental Chemical Corp New sub account/5910419101 Not for Resale. S5.SA-372/SA-372M 2007 SECTION II.`. S2.. Details of these supplementary requirements shall be agreed upon by the manufacturer and the purchaser. S4. and test temperature(s) shall be as specified..2 Acceptance criteria shall be specified and shall be in accordance with the applicable Code or purchaser’s specification and shall be included as part of the ordering information.. Ultrasonic Examination S5.2 Samples for grain size estimation shall be taken from the tension test specimen location.`.``. minimum energy values. S1.2 The necessary Code references toughness criteria and test temperature data shall be included in the ordering information. S4.`. Impact Testing S3. The number of specimens.. contract..``. S1.`.1 Specific fracture toughness requirements are levied by certain sections of the ASME Boiler and Pressure Vessel Code. S5.-`-`. S4.1 Rough machining shall be performed in the sequence and manner as specified. 08/13/2007 15:19:31 MDT . PART A SUPPLEMENTARY REQUIREMENTS One or more of the following supplementary requirements shall apply only when specified by the purchaser on the inquiry. Rough Machining S2. S3.`. Grain Size S1.1 Ultrasonic examination of forgings shall be carried out in accordance with Practice A 388/A 388M.```.