In this study, the average surface roughness values obtained when turning AISI 4140 grade tempered steel with a hardness of 51 HRC, were modeled using fuzzy logic, artificial neural networks (ANN) and multi-regression equations. Input variables consisted of cutting speed (V), feed rate (f) and depth of cut (a) while output variable was surface roughness (Ra). Fuzzy logic and ANN models were dev...

Wear losses have a great importance in the world machinery industry. They cause billions of dollars financial every year. Studies on surface treatments are increasing day by order to minimize wear materials. In this study, pack boronizing process was applied AISI 4140 and H13 steels, which frequently used manufacturing molding industry, using Ekabor II powder at 900 °C 950 for 4 6 hours. Micros...

A new method to generate large scale and highly dense nanoholes is presented in this paper. By the pulsed laser irradiation under water, the hydrogen etching is introduced to form high density nanoholes on the surfaces of AISI 4140 steel and Ti. In order to achieve higher nanohole density, laser shock peening (LSP) followed by recrystallization is used for grain refinement. It is found that the...

Abstract– In the present paper, the effect of heat treatment on the surface roughness of AISI 4140 steel has been investigated by use of paired t-test and one way analysis of variance (ANOVA). The paired t-test was performed to determine the differences between the means before and after heat treatment. One way ANOVA was used to further evaluate the effect of heat treatment on the difference in...

Case-hardening steels (EN36, 16MnCr5, and AISI 4140) are used in applications demanding good surface properties such as precision gears, shafts, cam rollers. This study explores the formation of microcoatings to improve characteristics these using carbonitriding, which combines merits carburizing nitriding offer surfaces with enhanced hardness wear resistance. Taguchi’s L18 orthogonal array is ...

This study focuses on the processability of four low-alloy steels (AISI 4130, 4140, 4340 and 8620) via laser-based powder bed fusion (LB-PBF). In as-built condition, alloys consisted tempered martensite that was result an intrinsic heat treatment (IHT) during LB-PBF. terms defects, a distinct transition in porosity observed correlated to volumetric energy density (VED). At low VED, specimens co...