The Yield Point Elongation (YPE) was determined from the tensile tests.
According to Cottrell and Bilby, strain aging and the subsequent phenomenon, that is, yield point elongation, could be controlled by the concentration of the interstitial solute atoms and of the mobile dislocation density.
The correlation between the yield point elongation % and the fluting intensity is presented in Table 3.
Control of the thermomechanical parameters leads to desirable mechanical properties such as low yield point elongation.
Steel % rolling reduction Ferrite grain size ([micro]m) (790[degrees]C) Mild steel 30 27.15 60 15.9 Steel Ferrite grain Ferrite grain size ([micro]m) size ([micro]m) (830[degrees]C) (870[degrees]C) Mild steel 38.35 7.9 24.6 25.35 Table 3: Effect of the rolling temperature and the rolling reduction on yield point elongation and fluting intensity in mild steel.
Each stress-strain curve has a diffuse upper yield strength, followed by a long region of yield point elongation, also called a Luders strain.
The yield strengths of the UNS S17400 stainless steel are much lower, and the material exhibits extensive yield point elongation absent in 17-4PH stainless steel.
All strain related test results, such as offset yield/proof stress, yield point elongation
, r value and strain to failure are measured automatically.