ASTM A789 S32205 S31803 Stainless Steel Tubes Material Purchase Specification

Stainless Steel Feed Material

Preference for Yongxing Special Materials Technology or similar quality manufacturer (to be nominated if not Yongxing)

Feed material certificates to be issued to the buyer for approval prior to commencing production

PREN Pitting Corrosion Equivalent

Adequate corrosion resistance shall be achieved by ensuring the pitting resistance equivalent (PRE) exceeds 36 for all tubes.
The pitting resistance equivalent shall be calculated as follows and reported for each heat.
PRE = %Cr + (3.3 x %Mo) + (16 x %N)

Dimensional Tolerances

Outside Diameter – 38.1mm +/- 0.25mm
Wall Thickness – 1.65 +/-0.17mm
Length – 7315mm -nil +5mm

Surface Condition

All tubes shall be free of mill scale or any other oxide form that may reduce corrosion resistance in service.

Chemical Composition

The stainless steel shall STRICTLY conform to the chemical requirements of UNS S32205

Critical Pitting Temperature Corrosion Test

A sample from each lot shall be tested in accordance with ASTM A923 Test Method C, at 35°C for a 24-hour test period.

The resultant corrosion rate shall be less than 10mg/dm2 and the results shall be reported.

Microstructure

The microstructure shall consist of ferrite and austenite and the volume fraction of ferrite shall be in the range of 40 – 60% in with ASTM E563, the presence of any intermetallic phase in the microstructure is strictly prohibited.

Mechanical Properties

The tensile and hardness properties shall conform to those nominated by ASTM A789M for UNS S31803.
Flaring tests as specified by ASTM A789M shall also be conducted.
Conformance to these requirements shall be reported for each production lot.

Integrity Testing

Hydrostatic testing or appropriate non-destructive tests shall be undertaken to assure tube integrity in accordance with ASTM A789M
The manufacturer shall nominate the preferred method of testing

PMI Testing

100% PMI testing required

Material Certification

EN 10204 3.1 Mill certificates required and shall clearly document the results of the tests and inspections nominated by the Technical Specification Requirements and the requirements of ASTM A789M and shall be supplied for buyers approval prior to packing and despatch of the consignment ex-mill.
Specification numer – QM22-004-02 REV 5 to be clearly noted on the material certificate
In addition to the 3.1b certificate/s the manufacturer shall provide additional reports for;

· Critical Pitting Temperature (copy of complete test report required)
· Microstructure (copy of test complete report required)
· Integrity Test Method and Results (Hydrostatic Test or Eddy Current Test)

Sample Testing

3 samples per heat (500mm long) of the finished tube/s to be made available to the buyer upon completion of production to enable independent third party testing this will be performed at buyer cost.

Inspection

Buyer reserves the right to appoint at it’s own cost an independent third party to carry out inspection/s both during production and final inspection prior to packing.

Difference Between Duplex Steel S31803/S32205 and 316L
ASTM A789 ASME SA 789 S31803 S32205 S32101 S32750 S32760 S32304 S31500 S31260 Seamless Tubes
ASTM A790 ASME SA790 S31803 S32205 S32101 S32750 S32760 S32304 S31500 S31260 Seamless Pipe
EN 10216-5 1.4462 1.4362 1.4162 1.4410 1.4501 Seamless Tubes

ASTM A789 S32205 S31803 Stainless Steel Tubes Material Purchase Specification

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