This study investigated the performance of the grinding parameters used in the cylindrical grinding process of AISI 5140 steel and identified optimum grinding conditions via the Taguchi optimization method. Experiments were carried out via the L18 orthogonal array. Control factors for optimum surface roughness (Ra) values were determined by using the Taguchi method. Two different grinding wheels (SiC and Al2O3), three different cryogenic samples (CHT, DCTT-15 and DCTT-30) and depth of cuts (100, 200 and 300 μm) were selected as control factors. The cylindrical grinding test results showed that optimal Ra values were obtained on specimens cryogenically treated for 30 h (DCTT-30). Linear and quadratic regression analyses were conducted for the experimental results. The correlation coefficients (R2) were found to be 0.957 and 0.993 with linear and quadratic regression models, respectively. Finally, confirmation tests were performed and showed that the optimization had been successfully implemented.

This study investigated the performance of the grinding parameters used in the cylindrical grinding process of AISI 5140 steel and identified optimum grinding conditions via the Taguchi optimization method. Experiments were carried out via the L18 orthogonal array. Control factors for optimum surface roughness (Ra) values were determined by using the Taguchi method. Two different grinding wheels (SiC and Al2O3), three different cryogenic samples (CHT, DCTT-15 and DCTT-30) and depth of cuts (100, 200 and 300 μm) were selected as control factors. The cylindrical grinding test results showed that optimal Ra values were obtained on specimens cryogenically treated for 30 h (DCTT-30). Linear and quadratic regression analyses were conducted for the experimental results. The correlation coefficients (R2) were found to be 0.957 and 0.993 with linear and quadratic regression models, respectively. Finally, confirmation tests were performed and showed that the optimization had been successfully implemented.

Rotating shaft systems play many critical roles in rotating machinery. The performance of any rotating machinery is very dependent on vibrations generated by the rotating shaft. The selection of rotating shaft material is very important to meeting the enormous demand of industrial users on the capability of vibration resistance in rotating machinery. Recent requirements for using rotating shafts have heightened the need for the materials used. The heat treatment of material has received much attention over the last few decades. The research to date has tended to focus on material properties for resistance and strength rather than on dynamic behavior. The main objective of the present study is to experimentally investigate the role of induction surface hardening which is one of the most commonly used types of heat treatment on AISI 1045 steel dynamic behavior. Heat treatable AISI 1045 steel is among the most widely used in all industrial applications requiring more resistance and strength. It has received much attention over the past several decades due to its usage in rotating shafts, axles, crankshafts, and spindles. Induction surface hardening is used to sustain service life by increasing the surface hardness and vibration reliability of a material. Since induction hardened surface depth plays a very important part in the stability of the rotating shaft, three different hardened surface depths (0.5, 1.0, and 1.5 mm) are utilized. The results show that a hardened surface depth of 1.0 mm surprisingly and positively affects the dynamic behavior of the rotating shaft as compared to the hardened surface depths of 0.5 and 1.5 mm.

Cylindrical grinding operation is an important metal cutting process used as a finish process to achieve the surface quality and dimensional stability of the products. In this context, experimental work and statistical analysis in researches contribute to improve product quality of manufactured parts. Tempered steels are widely used for automotive components and manufacturing applications. The objective of this study is to analyze the surface roughness (Ra) values of cryogenically (cryo) treated and tempered steels in cylindrical grinding operation. According to the grinding experiments created by the Taguchi method, grinding wheels (Al2O3 and SiC), heat treated steel samples (HT, CT24, and CT36) and depth of cut (50, 100, and 150[Formula: see text][Formula: see text]m) were selected to determine the optimum surface roughness values of these steels. The results showed that significant improvements in Ra values of cryo-treated and tempered steels were observed. The lowest Ra values were obtained in cryo-treated sample (CT36) with SiC grinding wheel and depth of cut (50[Formula: see text][Formula: see text]m).

Many of today’s rotating shaft systems require the superior stability characteristics of a rotating shaft to prevent system instability. Rotating shaft material properties play a crucial role in the vibration behavior of rotating shaft systems. It is important to control vibrations in the systems because excessive vibration amplitudes can cause inefficiency and system failure. The objective of this study is to investigate the vibration damping capacity of a rotating shaft treated by various procedures (deep cryogenic treatment, induction hardening, hot forging, and conventional heat treatment) in order to see the effects of the treatment procedures. An AISI 4140 steel material for the rotating shaft was selected because it is the most widely used material in industry. The rotating shaft is supported on oil lubricated journal bearings rather than rolling element bearings as used in prior studies by the authors. The results showed that rotating shaft material damping capacity due to treatment processes plays a major role for the rotating shaft systems stability. It is observed that the vibration damping ability of the rotating shaft with induction hardening to dissipate mechanical vibration was superior to deep cryogenic treatment, especially to hot forging and conventional heat treatment processes. Also, the results indicate that the dynamics characteristics of the rotating shafts supported by oil lubricated journal bearings are different to those supported by rolling element bearings.