The choice of the chemical composition, except for P and S in grades other than grade requiring case ofwelding and having the s & W ix is left to the discretion of manufacturer it. For each ofO.O1 reduction Helow percent of carbon 0.25 percent, an increase de0. 04 percent of manganese above the maximum of + ecified will be allowed up to a maximum of 1.40 percent to 280 to 520 W category. The total content of these elements must not exceed 1.OOpercent in the case of grades with the W suffix. 1 test shock and bending are optional (see 13.3 and 13.4). Two grades W limit the chemical composition and can be ordered when ensuring ease of welding in a requirement. ‘) If measurable performance superior tbe stress, or 0.2 per cent of elasticity. Tubes bending must be of appropriate length, for the machines in which they will be Bent, and must have either a diameter of 25 mm or 25 mm x 20 mm rectangular section. The edges of the rectangular test specimen must be rounded to a radius not exceeding 1.5 mm and in the case of the rectangular test specimen the test must be performed by folding of the test on the thinner section piece.
Ultrasonic examination (see IS 7666), review of magnetic particles (see IS 3703), review of penetrating fluid (see IS 3658), and radiographic examination (see IS 2595). Unless otherwise provided in the following is one of the standards of acceptance: a) b) c) d) is IS IS is 9565 for the ultrasound, 10724 for inspection of magnetic particles, 11732 for penetrant inspection. and 12 938 for the x-ray inspection.