10.3 Testing of chemical composition
10.3.1 Couplings, pup joints and accessories
For couplings, pup joints and accessories the analyses requested shall be furnished by the steel manufacturer or processor and shall be taken from material in tubular or bar form.
10.3.2 Heat analyses
For Groups 1, 2 and 3, when requested by the purchaser, the manufacturer shall furnish a report giving the heat analysis of each heat of steel used in the manufacture of API 5CT CASING TUBING, coupling stock and couplings furnished on the purchase agreement. In addition the purchaser, upon request, shall be furnished the results of quantitative | analyses for other elements used by the manufacturer to control mechanical properties.
For Grade Q125, the manufacturer shall furnish a report giving the heat analysis of each heat of steel used in the manufacture of API 5CT CASING PIPE, coupling stock and couplings furnished on the purchase agreement. The report shall I include quantitative analyses for other elements used by the manufacturer to control mechanical properties.
10.3.3 Product analyses
Two tubular products from each heat used shall be analysed for product analyses. Product analyses shall be made by the manufacturer on the finished tubular product. For electric-welded products, the chemical analysis may be determined on samples of skelp.
Product analyses shall include the results of quantitative determinations of all elements listed in Table C.5 or Table E.5 plus any other elements used by the manufacturer to control mechanical properties.
For Groups 1,2 and 3, the product analyses shall be available to the purchaser on request.
For Group 4, the product analyses shall be provided to the purchaser.
10.3.4 Test method
Chemical composition shall be determined by any of the procedures commonly used for determining chemical I composition, such as emission spectroscopy, X-ray emission, atomic absorption, combustion techniques or wet analytical procedures. The calibration methods used shall be traceable to established standards. In case of conflict, chemical analyses shall be made in accordance with ISO/TR 9769 or ASTM A751.
10.3.5 Re-check of product analyses — All groups
If the product analyses of both lengths of tubular product representing the heat fail to conform to the specified requirements, at the manufacturer’s option either the heat shall stand rejected or all the remaining lengths in the heat shall be tested individually for conformance to the specified requirements. If only one of two samples fails, at the manufacturer’s option either the heat shall stand rejected or two re-check product analyses shall be made on two additional lengths from the same heat. If both re-check product analyses conform to the requirements, the heat shall be accepted except for the length represented by the initial analysis which failed.
If one or both of the re-check product analyses fail, at the manufacturer’s option the entire heat shall be rejected or each of the remaining lengths shall be tested individually. In the individual testing of the remaining lengths in any heat, analyses for only the rejecting element or elements need be determined. Samples for re¬check product analyses shall be taken in the same manner as specified for product analysis samples. The results of all re-check product analyses shall be provided to the purchaser when specified on the purchase agreement.
10.4 Tensile tests
10.4.1 Stress-relief temperature
For the purpose of tensile test frequency, stress-relief of tempered products shall not be considered “heat treatment” provided the stress-relief temperature is at least 56 °C (100 °F) below the final tempering temperature.
10.4.2 Heat-control tensile tests — Groups 1,2 and 3
One tensile test shall be made as a control on each heat of steel used by the manufacturer for the production of API 5CT CASING PIPE under this International Standard. For electric-welded pipe, these tensile tests shall be made on either the skelp or the finished API 5CT CASING PIPE , at the option of the manufacturer.
A heat-control test made on a length of API 5CT CASING PIPE may also be considered as a product test for the lot being tested.
10.4.3 Frequency of testing and location of test specimen — Casing and tubing
The frequency of testing for casing and tubing of all groups is defined in Table C.40 or Table E.40.
Additional requirements for PSL-2 and PSL-3 products are specified in Annex H.
The lengths for testing shall be selected at random and, when more than one test is required, the selection procedures shall provide samples representing the start and end of the heat-treat cycle (as applicable) and front and back ends of the tubes. When more than one test is required, the test specimens shall be from different lengths, except for upset API 5CT CASING PIPE the test specimens may be taken from both ends of one length.