A strain distribution analysis was carried out on hot forged seamless pipe
fittings produced at a factory, The studies were conducted on pipe preforms
, cut from a seamless pipe, which had a grid inscribed on the outside surfa
ce. The dimensions of the individual cells were measured before processing
of the preforms and, once the parts had cooled down to room temperature, th
e dimensions of the distorted grids were recorded. The different components
of strain were evaluated from both sets of measurements. Thermal evolution
during forging was recorded by inserting a series of type K thermocouples
into the preforms and logging the data into a computer system, Two preforms
were loaded together in a single trial, whereas a third one was deformed b
y itself to evaluate the consistency of the process. Results from the analy
sis compare favourably with measurements of the change in wall thickness ob
tained by ultrasonic means in one of the pieces. MST/4414.