Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Stainless Steel

Burr Formation Mechanisms During Drilling Operations Of Low Carbon And Stainless Steels

Samir Ali Amin Alrabii

Engineering and Technology Journal, 2016, Volume 34, Issue 6, Pages 1104-1115

In drilling operations, burrs cause many problems for product quality and functionality. Therefore, understanding of burr formation mechanism is essential in order to reduce the deburring cost by reducing burr formation. Also, to avoid or minimize the burr formation during drilling, it is necessary to realize the relationship between the burr formation mechanism and the cutting parameters involved in the machining operations. Therefore, this research is an attempt to investigate experimentally the influence of using a wide range of cutting speeds, feed rates, and depth of cuts on the burr formation mechanism in drilling operations of low carbon and stainless steels plates using HSS cutting tools and cutting fluids. Additionally, this study was focused on the effect of these cutting parameters on the burr size and type. Thus, the average heights of exit formed burrs were measured at different machining conditions.Two types of burr mainly formed and observed (transient and uniform burrs) during drilling both steels. Accordingly, two types of burr formation mechanism related to these observed types of burr were explained. It was found that the average burr height for both steels generally reduced with increasing cutting speedsand feeds due to the change of burr type from a transient burr at lower cutting speeds and feeds to a uniform burr with and without a drill cap at higher speeds and feeds. Finally, no crown burr type formed and observed during drilling both steels in comparison with previous works.

Fe Analysis of Residual Stresses Induced by Spot Welding of Stainless Steel Type Aisi 316

Ahmed N. Al-Khazraji; Samir A. Al-Rabii; Ali Hussein F. Al-Jelehawy

Engineering and Technology Journal, 2014, Volume 32, Issue 2, Pages 365-384

Specimens of the as-received stainless steel type 316, according to AISI standard, in form of sheet with 1.5 mm thickness were first spot welded and thenshot peened to obtain the influence of shot peening process on the residual stresses induced by spot welding process. X-Ray Diffraction (XRD) method was used to measure the residual stresses. Also, a finite element method (FEM) was employed by ANSYS software version 11 to achieve the simulations for transient thermal analysis and residual stresses analysis in all cases. In addition, the temperature dependency of materials properties was used to assess its effects on the final residual stress results. A comparison showed a very good agreement between the experimental and the numerical results due to the total elimination of tensile residual stresses and creating the compressive type instead.

Formation of Compressive Residual Stresses by Shot Peening for Spot Welded Stainless Steel Plates

Ali H. Fahem; Samir Ali Al-Rabii; Ahmed Naif Al-Khazraji

Engineering and Technology Journal, 2013, Volume 31, Issue 11, Pages 2198-2211

In this paper, a stainless steel 316 was selected for this study and tested to obtain its chemical composition, mechanical properties and stress relieving. Then, two plates (55*55*1) mm were first joined by spot welding and later tested by X-Ray diffraction (XRD) machine to measure the tensile residual stresses formed due to thermal effect. In order to remove the tensile residual stresses, a shot peening process for these spot welded plates was made to create the compressive residual stresses which will improve the life of spot welded part during the service. The results of the x-ray diffraction tests exhibited that only compressive residual stresses formed in the shot peened spot welded plates.