Evaluation of the Resistance of Type 316 Stainless Steel Against Progressive Deformation

Abstract

An experimental program has been conducted on Type 316 stainless steel uniaxial specimens to determine the main characteristics of their behavior under repeated loading. The cyclic stress-strain curve measured under constant repeated load, without high preloads, is independent of the level of the mean stress. Two different behaviors with respect to the occurrence of progressive deformation have been observed: (1) at room temperature, progressive deformation occurs when the maximum value of the tensile stress exceeds a critical value, and (2) at 320°C and for loading with temperature cycling between ambient temperature and 320°C, progressive deformation occurs when the amplitude of stress exceeds a critical value. These results show that Section III of the ASME Code, which limits the range of variation of the primary plus secondary stress intensity to the value of 3 Sm, gives an effective guarantee against progressive deformation for operating conditions in the range of 20 to 320°C. It is recalled that the absence of progressive deformation is a necessary condition for the validity of conventional low-cycle fatigue analysis.

A review of some plasticity and viscoplasticity constitutive theories

“…Instead of using a nonlinear dependency (of the back-stress norm) in the dynamic recovery term, it was proposed by Chaboche (1991) to introduce a threshold. This was justified by the commonly observed existence (Plénard and Fromont, 1987;Pelissier-Tanon et al, 1980), of a limit of accommodation, both in terms of the mean-stress and of stress amplitude. The structure of the additional back-stress evolution equation is then:…”

Ambient multiaxial creep: shakedown analysis of structures using stereo digital image correlation

“…A cycle is defined from time t to t + T (T is the period of the cycle and t is the current time). If in eq (t) is approaching "zero" (in most cases it is necessary to define a threshold, which in this paper is 1.0 ⋅ 10 −8 ∕s ), the behavior of the structure can be defined as shakedown [62][63][64]. (5) in eq (t) = p eq (t) + cr eq (t),…”

Two Parameters Describing Cyclic Hardening/Softening Behaviors of Metallic Materials

“…If r b =r 0:2 is smaller than 1.2, the alloy behaves in a cyclic softening manner. Table 1 lists the tensile properties of 40 alloys as well as their cyclic hardening/softening behavior (Ref 4,5,(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25)(26)(27)(28)(29). In the table, n is the strain-hardening exponent, while H/S represents the cyclic hardening/softening behavior of the alloys.…”