Impression Creep: An Innovative Small Specimen Test Technique for Characterizing Creep Deformation Behavior of Materials

抄録

Impression creep (IC) studies were conducted on different heats of 316LN stainless steel (SS) base materials and welded joint in the temperature range 898-923 K, in the punching stress range 472-760 MPa, using specimens of nominal size 10x10x10 mm. The IC curves showed a primary and steady-state creep stages. The stress and temperature dependence of the steady-state impression velocity followed Norton power-law and Arrhenius rate equation, respectively, and indicated dislocation creep mechanism. The heat-affected zone (HAZ), weld metal (WM) and base metal (BM) of the welded joint revealed distinct creep behaviour owing to their different microstuctures. Equivalence between the IC test and uniaxial creep (UC) test parameters was established. The paper discusses the results of IC studies and highlights the potential applications of the IC test technique.