Showing papers in "Isij International in 1969"

Effect of Shear Strain Rate on the Susceptibility of Selected Engineering Alloys to Plastic Instability in Torsion

Abstract: The effect of shear strain ratp ill torsion on the sllscejJtibility to plastic imtability in Imre shear was studied in A / Sf 43-10 steel at tensile strength levels of /80 alld 220 ksi, unalloyed titanium, Ti6A I4V, Ti-13\!I I Cr-3AI, and 7075 aluminum alloy, using (l range of shear slrain rates of 0.007 10 2.81 lIlinJ. The steel showed ilil/lOrtallt delJendellCY on strain rate, whereas the nonferrolls ailo)'s were relativel) insensitive. A critical strain rate was observed for the steel at 180 k,i . below which 110 illstabilil)' balld forms bifore filial .Factllre. The nonferrOIiS alloys cOllsiJtently formed a single strollg instability band illllllediate(y IJrior to Factllre, and showed straill hardening res/Jonse II/J to the final strong instability. The high strength steel showed more tolerance to instability bands prior to filial {ractll/'e, as com/Jared to the nonferrolls alloys. The shearing instability bands are demonstrated to IJenetrate 10 Ihe center q/ Ihe >/JeCilllell, and are IIOt merely swface /Jhenolllena .