Improving the Shape Memory Effect of a Fe-Mn-Si-Cr-Ni Alloy through Shot Peening

Abstract

To improve the shape memory effect, the solutionized Fe-24Mn-6Si-9Cr-6Ni alloy was shot peened and subsequently annealed. The phase constituent was examined using the X-ray diffraction method. Microstructure evolution was characterized using an optical microscope and the electronic backscatter diffraction method, and the shape memory effect was evaluated using a bending test. The results show that α′-martensite and ε-martensite were introduced into the shot-peened surface layer. The α′-martensite remained after annealing even at 850 °C. Microstructure of the surface layer was refined through shot peening and subsequent annealing. Compared with those of the solutionized specimen, the shape recovery ratio and recovery strain of the specimens that are shot peened and subsequently annealed are significantly improved at different prestrains.

The effect of shot peening on the contact fatigue performance of C40 steel gears after laser surface melting

“…Additionally, figures 5(a)-(c) demonstrate the varying effects of different SP parameters on the microstructure and grain refinement within the plastic deformation layer. Studies conducted by Yang Huanping et al [34] and Moradi Ali et al [35] have observed that SP treatment contributes to the refinement of the microstructure in materials such as Fe-24Mn-6Si-9Cr-6Ni alloy and Ti-6Al-4V alloy. In their pursuit of accurately predicting the relationship between SP parameters and grain size, Wang et al [36] even established a coupling model for this purpose.…”

Thermodynamic modeling and computational predictions of NbC precipitation in Fe–Mn–Si-based shape memory alloys by the classical nucleation and growth theories

“…where A Nb and A C are the atomic mass of Nb and C, respectively. Using equations (11) and (12), W e Nb and W e C can be calculated.…”

“…Given an initial composition of the Fe-Mn-Si-based shape memory alloys, the solubility product KSP of NbC at temperature T is determined through equation (10). The equilibrium weight fractions W e Nb and W e C are solved by equations (11) and (12). Then, the driving force G v D for nucleation can be calculated by equation (2).…”

“…However, the recovery strain of the polycrystalline Fe-Mn-Si-based alloy obtained by conventional manufacturing process consisting of forging, rolling, and subsequent solution treatment is only 2%-3%, which cannot meet the engineering application requirements. Modification of alloying elements [7,8], heat treatment [9][10][11], plastic deformation [12][13][14], thermomechanical processing [15], training treatment [16], and second-phase precipitation [17][18][19][20] have been employed to improve the shape recovery strain. The precipitation of nanosized second-phase was first proposed by Kajiwara as an effective method to improve the shape memory effect in Fe-Mn-Si-based alloys [17,21].…”

Achievements and Perspectives on Fe-Based Shape Memory Alloys for Rehabilitation of Reinforced Concrete Bridges: An Overview

“…When SMAs are subjected to external force, a stress-induced martensite transformation occurs, and the macroscopic transformation is the deformation of the alloy. Martensite reverse transformation is activated when the temperature rises to A s , and the alloy can almost completely recover to its original shape when the temperature reaches above A f [15][16][17][18]. The SME is reflected in this process, as shown by the red curve in Figure 1.…”