Material under this standard named as WP Grade, and for each WP grade stainless steel, several categories of pipe fittings are included, to indicate that a seamless or welded structure is used. Class designations are also used to indicate non-destructive testing methods and the extent of non-destructive testing (NDE).
Heat treatment
For H grade steel, separate solution heat treatment are required for solution annealing. All pipe fittings should be supplied in heat treated condition. All welding work should be done before heat treatment. Fitting that have been machined directly from solution annealed forgings and bar stocks do not need to be annealed again.
ASTM A403 Standard Scope
The standard includes several grades of austenitic stainless steel alloys, and uses the WP or CR prefix to mark the grade of steel, depending on the applicable ASTM or MSS size and rated pressure standards.
ASTM A403 is designed for forged steel pipe fittings, Cast pipe fittings are not suitable. (Austenitic stainless steel castings are included in these standard, A351/A351M, A743/A743M and A744/A744M.)
ASTM A403 Stainless Steel Pipe Fittings
ASTM A403 Stainless Steel Pipe Fittings refers to the material of forged and rolled austenitic stainless fittings for pressure pipes. Common grades are WP304/L, WP316/L. They can be used into many fields as engineering industry, energy conversion plants etc.
Tensile Properties
The tensile properties of the pipe fitting materials shall comply with the tensile properties requirements. Tests and reports shall be conducted in accordance with A370 methods and definitions.
For tensile testing, longitudinal or transverse cut specimens should be acceptable. Although tensile properties Table specifies the elongation requirements for the longitudinal and transverse specimens, it is not intended to be applicable at the same time. Instead, This intent that only the corresponding elongation requirements for specimens that are applicable in the direction are appropriate.
Chemical Composition
The chemical composition of each cast or furnace steel shall be determined and shall comply with the chemical composition requirements for each grade of material listed in the chemical composition table.
Tensile Properties
The tensile properties of the pipe fitting materials shall comply with the tensile properties requirements. Tests and reports shall be conducted in accordance with A370 methods and definitions.
For tensile testing, longitudinal or transverse cut specimens should be acceptable. Although tensile properties Table specifies the elongation requirements for the longitudinal and transverse specimens, it is not intended to be applicable at the same time. Instead, This intent that only the corresponding elongation requirements for specimens that are applicable in the direction are appropriate.
Tensile Properties
The tensile properties of the pipe fitting materials shall comply with the tensile properties requirements. Tests and reports shall be conducted in accordance with A370 methods and definitions.
For tensile testing, longitudinal or transverse cut specimens should be acceptable. Although tensile properties Table specifies the elongation requirements for the longitudinal and transverse specimens, it is not intended to be applicable at the same time. Instead, This intent that only the corresponding elongation requirements for specimens that are applicable in the direction are appropriate.
Tensile test report made on the starting material shall notes:
• The starting material report shall demonstrate that the properties of the pipe fittings material meet the requirements of this standard, provided that the heat treatment of the initial material is the same as that of the pipe fittings material.
• If the initial material has not been tested, or if the heat treatment of the initial material is different from that of the pipe fittings, the fitting manufacturer shall conduct at least one tensile test per furnace steel on the material representing of the finished pipe fittings, and the heat treatment condition shall be the same as that of the pipe fittings represented.
Standard Specification for Wrought Austenitic Stainless Steel Piping Fittings
Abstract
This specification covers the standard for wrought austenitic stainless steel fittings for pressure piping applications. The material for fittings shall consist of forgings, bars, plates, or seamless or welded tubular products. Forging or shaping operations shall be performed by hammering, pressing, piercing, extruding, upsetting, rolling, bending, fusion welding, machining, or by a combination of two or more of these operations. All fittings shall undergo heat-treatment. Chemical and product analyses shall be performed and shall conform to the required chemical composition in carbon, manganese, phosphorus, sulfur, silicon, chromium, molybdenum, and titanium. Tension test shall be done on the fitting material to determine the tensile properties such as yield strength and tensile strength. Fittings supplied under this specification shall be examined visually for surface discontinuities, surface checks, and mechanical marks.
1. Scope
1.1 This specification covers wrought stainless steel fittings for pressure piping applications.2
1.2 Several grades of austenitic stainless steel alloys are included in this specification Grades are designated with a prefix, WP or CR, based on the applicable ASME or MSS dimensional and rating standards, respectively.
1.3 For each of the WP stainless grades, several classes of fittings are covered, to indicate whether seamless or welded construction was utilized. Class designations are also utilized to indicate the nondestructive test method and extent of nondestructive examination (NDE). Table 1 is a general summary of the fitting classes applicable to all WP grades of stainless steel covered by this specification. There are no classes for the CR grades. Specific requirements are covered elsewhere.
1.4 This specification is expressed in both inch-pound units and in SI units. However, unless the order specifies the applicable “M” specification designation (SI units), the material shall be furnished to inch-pound units.
1.5 The values stated in either SI units or inch-pound units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
1.6 This specification does not apply to cast steel fittings. Austenitic stainless steel castings are covered in Specifications A351/A351M, A743/A743M, and A744/A744M.
1.7 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.
Chemical Composition (%) of ASTM A403
| Steel No. | Type | Chemical composition | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| C | Si | S | P | Mn | Cr | Ni | Mo | Other | ób | ós | δ5 | |||
| WP304 | 0.08 | 1 | 0.03 | 0.045 | 2 | 18-20 | 8-11 | 515 | 205 | 28 | ||||
| WP304H | 0.04-0.1 | 1 | 0.03 | 0.045 | 2 | 18-20 | 8-11 | 515 | 205 | 28 | ||||
| WP304L | 0.035 | 1 | 0.03 | 0.045 | 2 | 18-20 | 8-13 | 485 | 170 | 28 | ||||
| WP304LN | 0.03 | 0.75 | 0.03 | 0.045 | 2 | 18-20 | 8-10.5 | N2:0.1-0.16 | 515 | 205 | 28 | |||
| WP304N | 0.08 | 0.75 | 0.03 | 0.045 | 2 | 18-20 | 8-11 | N2:0.1-0.16 | 550 | 240 | 28 | |||
| WP309 | 0.15 | 1 | 0.03 | 0.045 | 2 | 22-24 | 12-15 | 515 | 205 | 28 | ||||
| WP310 | 0.15 | 1.5 | 0.03 | 0.045 | 2 | 24-26 | 19-22 | 515 | 205 | 28 | ||||
| WP316 | 0.08 | 1 | 0.03 | 0.045 | 2 | 16-18 | 10-14 | 2-3 | 515 | 205 | 28 | |||
| WP316H | 0.04-0.1 | 1 | 0.03 | 0.045 | 2 | 16-18 | 10-14 | 2-3 | 515 | 205 | 28 | |||
| WP316LN | 0.03 | 0.75 | 0.03 | 0.045 | 2 | 16-18 | 11-14 | 2-3 | N2:0.1-0.16 | 515 | 205 | 28 | ||
| WP316L | 0.035 | 1 | 0.03 | 0.045 | 2 | 16-18 | 10-16 | 2-3 | 485 | 170 | 28 | |||
| WP316N | 0.08 | 0.75 | 0.03 | 0.045 | 2 | 16-18 | 11-14 | 2-3 | N2:0.1-0.16 | 550 | 240 | 28 | ||
| WP317 | 0.08 | 1 | 0.03 | 0.045 | 2 | 18-20 | 11-15 | 3-4 | 515 | 205 | 28 | |||
| WP317L | 0.03 | 1 | 0.03 | 0.045 | 2 | 18-20 | 11-15 | 3-4 | 515 | 205 | 28 | |||
| WP321 | 0.08 | 1 | 0.03 | 0.045 | 2 | 17-20 | 9-13 | Ti:5C-0.7 | 515 | 205 | 28 | |||
| WP321H | 0.04-0.1 | 1 | 0.03 | 0.045 | 2 | 17-20 | 9-13 | Ti:4C-0.7 | 515 | 205 | 28 | |||
| WP347 | 0.08 | 1 | 0.03 | 0.045 | 2 | 17-20 | 9-13 | Nb+Ta:10C-1.1 | 515 | 205 | 28 | |||
| WP347H | 0.04-0.1 | 1 | 0.03 | 0.045 | 2 | 17-20 | 9-13 | Nb+Ta:8C-1 | 515 | 205 | 28 | |||
| WP348 | 0.08 | 1 | 0.03 | 0.045 | 2 | 17-20 | 9-13 | Ta:0.1 | 515 | 205 | 28 | |||
| WP348H | 0.04-0.1 | 1 | 0.03 | 0.045 | 2 | 17-20 | 9-13 | Ta:0.1 | 515 | 205 | 28 | |||
Notes:
- For each reduction of 0.01% below the specified C maximum, an increase of 0.06% Mn above the specified maximum will be permitted, up to a maximum of 1.35%.
- The sum of Cu, Ni, Cr, and Mo shall not exceed 1.00%.
- The sum of Cr and Mo shall not exceed 0.32%.
- The maximum carbon equivalent (C.E.) shall be 0.50, based on heat analysis and the formula C.E.=C+Mn/6+(Cr+Mo+V)/5+(Ni+Cu)/15.
Material Furnished to this specification shall conform to the requirements of specifications A960/A960M including any supplementary requirements that are indicates in the purchase order . Failure to company with the common requirements of Specification A960/A960M constitutes non-conformance with this specification . In case of conflict between this specification and Specification A960/A960M , this specification shall prevail .
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