Hi Every Body.

Greetings to All.

Below is UCS-79 details.

Any body can little elaborately explain the below conditions particularly condition 4.


For P-No. 1 Group Nos. 1 and 2 materials the extreme fiber elongation
may be as great as 40% when none of the following conditions
exist:
(1) The vessel will contain lethal substances either
liquid or gaseous (see UW-2).
(2) The material is not exempt from impact testing
by the rules of this Division or impact testing is required
by the material specification.
(3) The thickness of the part before cold forming
exceeds 5⁄8 in. (16 mm).
(4) The reduction by cold forming from the as-rolled
thickness is more than 10% at any location where the
extreme fiber elongation exceeds 5%.
(5) The temperature of the material during forming
is in the range of 250°F to 900°F (120°C to 480°C).

Thanks in advance.

Muru

Hi,

I think what the code says is the following:
For all carbon and low alloy steels, the maximum extreme fiber elongation is limited to 5% without heat treatment. For P-No. 1, Groups Nos. 1 and 2, the maximum extreme fiber elongation may be 40% without heat treatment, provided UCS-79(d) is met.