304 Stainless Steel Pipe ASTM A312 304 Stainless Steel Seamless Pipe SS Pipes 304 Stainless Steel Piping

304 Stainless Steel Pipe is the standard “18/8” stainless steel; it is the most versatile and most widely used stainless steel, available in a wider range of products, forms and finishes than any other. It has excellent forming and welding characteristics. The balanced austenitic structure of Grade 304 enables it to be severely deep drawn without intermediate annealing, which has made this grade dominant in the manufacture of drawn stainless steel part such as sink, hollow-ware and saucepan. For these application it is common to use special “304DDQ” (Deep Drawing Quality) variants.

Grade 304 Pipe is readily brake or roll formed into a variety of components for application in the industrial, architectural, and transportation fields. Grade 304 also has outstanding welding characteristic. Post-weld annealing is not required when welding thin sections.

Grade 304L, the low carbon version of 304, does not require post-weld annealing and so is extensively used in heavy gauge component (over about 6mm). Grade 304H with its higher carbon content finds application at elevated temperature. The austenitic structure also gives these grades excellent toughness, even down to cryogenic temperature.

Table 1. Composition ranges for ASME SA 312 ASTM A312 304 304L 304H and EN 10216-5 1.4301 1.4307 1.4948

304 Stainless Steel Pipe Mechanical Properties

Typical mechanical properties for grade 304 stainless steels are given in table 2.

Table 2. 304 Stainless Steel Pipe Mechanical properties

304H also has a requirement for a grain size of ASTM No 7 or coarser.

304 Stainless Steel Pipe Physical Properties

Typical physical properties for annealed grade 304 stainless steels are given in table 3.

Table 3. Physical properties of 304 grade stainless steel in the annealed condition

ASTM A312 seamless stainless steel pipes for general corrosive service

We manufacturing and supply seamless austenitic stainless steel pipes intended for high-temperature and general corrosive service.

Grades 304H, 309H, 310H, 316H, 321H, 347H are intended for high-temperature service.

Optional supplementary requirements are provided for pipe where a greater degree of testing is desired. There supplementary requirements call for additional tests to be made and, when desired, one or more of these may be specified in the order.

The standardized dimensions of seamless stainless steel pipe as shown in ANSI B36.19. These dimensions are also applicable to heavily cold worked pipe. Pipe having other dimensions may be furnished provided such pipe complies with all other requirements of this specification.

Grades TP321 and TP321H have lower strength requirements for pipe manufactured by the seamless process in nominal wall thicknesses greater than 3/8 in. [9.5 mm].

ASTM A312 seamless stainless steel pipes for general corrosive service

We manufacturing and supply seamless austenitic stainless steel pipes intended for high-temperature and general corrosive service.

Grades 304H, 309H, 310H, 316H, 321H, 347H are intended for high-temperature service.

Optional supplementary requirements are provided for pipe where a greater degree of testing is desired. There supplementary requirements call for additional tests to be made and, when desired, one or more of these may be specified in the order.

The standardized dimensions of seamless stainless steel pipe as shown in ANSI B36.19. These dimensions are also applicable to heavily cold worked pipe. Pipe having other dimensions may be furnished provided such pipe complies with all other requirements of this specification.

Grades TP321 and TP321H have lower strength requirements for pipe manufactured by the seamless process in nominal wall thicknesses greater than 3/8 in. [9.5 mm].

Referenced documents

1. ASTM Standards

A 262 Practices for Detecting Susceptibility to Intergranular Attack in Austenitic Stainless Steels

A 370 Test Methods and Definitions for Mechanical Testing of Steel Products

A 450/A 450M Specification for General Requirements for Carbon, Ferritic Alloy, and Austenitic Alloy Steel Tubes

A 941 Terminology Relating to Steel, Stainless Steel, Related Alloys, and Ferroalloys

A 999/A 999M Specification for General Requirements for Alloy and Stainless Steel Pipe

E 112 Test Methods for Determining the Average Grain Size

E 381 Method of Macroetch Testing Steel Bars, Billets, Blooms, and Forgings

E 527 Practice for Numbering metals and Alloys (UNS)4

2. ANSI Standards

B1.20.1 Pipe Threads, General Purpose

B36.10 Welded and Seamless Wrought Steel Pipe

B36.19 Stainless Steel Pipe

3. ASME Standard

ASME Boiler and Pressure Vessel Code: Section VIII

Ordering Information

1. Orders for material to this specification should include the following, as required, to describe the desired material adequately:

1.1 Quantity (feet, centimetres, or number of lengths),

1.2 Name of material (austenitic steel pipe),

1.3 Process (seamless (SML) or welded (WLD) or heavily cold worked (HCW) ),

1.4 Grade (Table 1),

1.5 Size (NPS or outside diameter and schedule number or average wall thickness),

1.6 Length (specific or random) (Section 13),

1.7 End finish (Section on Ends of Specification A 999/A 999M),

1.8 Optional requirements (product analysis, see Section 8; hydrostatic or nondestructive electric test),

1.9 Test report required (Certification Section of Specification A 999/A 999M),

1.10 Specification number, and

1.11 Special requirements or any supplementary requirements selected, or both.

Materials and Manufacture

1. Manufacture:

1.1 The pipe shall be manufactured by one of the following processes:

1.2 Seamless pipe shall be made by a process that does not involve welding at any stage of production.

1.3 At the option of the manufacturer, pipe shall be either hot finished or cold finished.

1.4 The pipe shall be free of scale and contaminating exogenous iron particles. Pickling, blasting, or surface finishing is not mandatory when pipe is bright annealed. The purchaser is permitted to require that a passivating treatment be applied to the finished pipe.

2. Heat Treatment- All pipe shall be furnished in the heat-treated condition. Alternatively, for seamless pipe, immediately following hot forming while the temperature of the pipes is not less

than the specified minimum solution treatment temperature, pipes may be individually quenched in water or rapidly cooled by other means.

3. Grain Size:

3.1 The grain size of grades TP309H, TP309HCb, TP310H and TP310HCb, as determined in accordance with Test Methods E 112, shall be No. 6 or coarser.

3.2 The grain size of grades 304H, 316H, 321H, 347H, as determined in accordance with Test Methods E 112, shall be No. 7 or coarser.

Hydrostatic or Nondestructive Electric Test

1. Each pipe shall be subjected to the nondestructive electric test or the hydrostatic test. They type of test to be used shall be at the option of the manufacturer, unless otherwise specified in the purchase order.

2. The hydrostatic test shall be in accordance with Specification A 999/A 999M, unless specifically exempted under the provisions of 3.

3. For pipe whose dimensions equal or exceed NPS10, the purchaser, with the agreement of the manufacturer, may waive the hydrostatic test requirement when in lieu of such test the purchaser performs a system test. Each length of pipe furnished without the completed manufacturer’s hydrostatic test shall include with the mandatory markings the letters “NH.”

4. Nondestructive Electric Test:

Nondestructive electric tests shall be in accordance with Specification A 999/A 999M.

Lengths

1. Pipe lengths shall be in accordance with the following regular practice:

1.1 Unless otherwise agreed upon, all sizes from NPS 1/8 to and including NPS 8 are available in a length up to 24 ft (Note 4) with the permissible range of 15 to 24 ft (Note 4). Short lengths are acceptable and the number and minimum length shall be agreed upon between the manufacturer and the purchaser.

1.2 If definite cut lengths are desired, the lengths required shall be specified in the order. No pipe shall be under the specified length and not more than 1/4 in. [6 mm] over that specified.

1.3 No jointers are permitted unless otherwise specified.

Marking

In addition to the marking specified in Specification A 999/A 999M, the marking shall include the NPS (nominal pipe size) or outside diameter and schedule number or average wall thickness, heat number, and NH when hydrotesting is not performed and ET when eddy-current testing is performed or UT when ultrasonic testing is performed. The marking shall also include the manufacturer’s private identifying mark For Grades TP304H, TP316H, TP321H, TP347H, TP348H, and S30815, the marking shall also include the heat number and heat-treatment lot identification. If specified in the purchase order, the marking for pipe larger than NPS 4 shall include the weight.