Time limit

The time yield strength  ( formula symbol ) is the stress that leads to a certain plastic strain at a predetermined temperature and duration of stress . ${\displaystyle R_{p}}$

As in the tensile test , the symbol R is used. The index for plastic is supplemented by the parameters of the experiment: ${\displaystyle _{p}}$

• the relative value of the plastic elongation
• the duration of the exposure
• the temperature.

For example, the time yield strength determined at 12,000 hours, 600 ° C and a resulting plastic elongation of 0.1% is denoted by the abbreviation . ${\displaystyle R_{p\;0,1/12000/600}}$