Steel vesselsU.K.
5. Non-alloy quality steels must meet the following requirements—
(a)they must be non-effervescent and supplied after normalisation treatment, or in an equivalent state;
(b)the content per product of carbon must be less than 0.25% and that of sulphur and phosphorous must each be less than 0.05%
(c)they must have the following mechanical properties per product—
(i)the maximum tensile strength Rm, max must be less than 580 N/mm2;
(ii)the elongation after fracture must be:
if test pieces are taken parallel to the direction of rolling:
| thickness ≥ 3 mm: | A | ≥ 22%, |
| thickness < 3 mm: | A 80 mm | ≥ 17%, |
or, if test pieces are taken perpendicular to the direction of rolling:
| thickness ≥ 3 mm: | A | ≥ 20%, |
| thickness < 3 mm: | A80 mm | ≥15%, |
(iii)the average bending rupture energy (KCV) for three longitudinal test pieces at minimum working temperature must not be less than 35 J/cm2. Not more than one of the three figures may be less than 35 J/cm2, with a minimum of 25J/cm2. In the case of steels intended to be used in the manufacture of vessels the minimum working temperature of which is lower than - 10°C and the wall thickness of which exceeds 5 mm, this property must be checked.