Analysis of residual stresses resulting from the surface preparation for X-ray diffraction measurement

Abstract

There is no consensus in the literature on the need to remove preprocessing layers from the material prior to the measurement of residual stresses by X-ray diffractometer. Thus, the purpose of this work was to evaluate the residual stresses induced by material preprocessing and its evolution during the preparation of the surface by electrolytic removal. Sample surfaces were pre-processed by grinding and sandblasting and the resulting residual stresses were measured by X-ray diffractometry. At each removal stage, the evolution of residual stresses, hardness and microstructure of the surface were verified. It was concluded that different preprocessing methods can induce surface residual stresses of either tension or compression, reaching different depths. Removal by electrolytic method of the modified layer has shown itself capable of reducing significantly the magnitude of the residual stresses induced by preprocessing. On the other hand, the depth of deformed grains or surface hardness proved to be incapable of predicting the depth of induced residual stresses. Finally, it was discussed whether or not the layers removed by this method reveal the subsurface stresses and if the removal should take place before or after a second processing.

Mechanical and Tribological Characteristics of Cladded AISI 1045 Carbon Steel

“…As shown in Figure 7c,d, the hardness of the top surface was lower than the subsurface, which may be attributed to the annealing and cooling mechanisms, which are dependent on the temperature of the layers with respect to depth during AM. Moreover, the induced residual stress could be responsible for the lower surface hardness in comparison with the subsurface [32]. The mechanism of the increase in surface hardness with respect to depth is a result of grain size refinement and work hardening induced by plastic strain [33].…”

“…Specifically, in AM materials, the elimination of surface defects such as porosities, cracks, etc., may also be responsible for the increase in surface hardness with respect to depth [34]. responsible for the lower surface hardness in comparison with the subsurface [32]. The mechanism of the increase in surface hardness with respect to depth is a result of grain size refinement and work hardening induced by plastic strain [33].…”

Effect of cutting parameters on surface residual stresses in dry turning of AISI 1035 alloy

“…Many attempts have been done to figure out the relationship between different cutting parameters/conditions and the induced RSes using experimental [6][7][8], analytical modeling [9][10][11], finite element modeling [12][13][14], and various combinations of them [15][16][17] in various machining operations [18][19][20]. The experimental investigations were carried out via measuring the RSes using different measuring methods such as ring core method [21], hole drilling technique [22], deep-hole drilling [23], slope cutting method [24], contour method [25], synchrotron diffraction [26] method, XRD method [27], and neutron diffraction method [28]. Among all these measuring techniques, XRD and hole drilling technique are the most commonly used in machining applications.…”