Wear Mechanism of Multilayer Coated Carbide Cutting Tool in the Milling Process of AISI 4340 under Cryogenic Environment

Cryogenic technique is the use of a cryogenic medium as a coolant in machining operations. Commonly used cryogens are liquid nitrogen (LN2) and carbon dioxide (CO2) because of their low cost and non-harmful environmental impact. In this study, the effects of machining conditions and parameters on the wear mechanism were analysed in the milling process of AISI 4340 steel (32 HRC) under cryogenic conditions using a multilayer coated carbide cutting tool (TiAlN/AlCrN). A field emission scanning electron microscope with energy-dispersive X-ray analysis was used to examine the wear mechanisms comprehensively. At low machining parameters, abrasion and adhesion were the major wear mechanisms which occurred on the rake face. Machining at high machining parameters caused the removal of the coating material on the rake face due to the high temperature and cutting force generated during the cutting process. In addition, it was found that continuously adhered material on the rake face would lead to crater wear. Furthermore, the phenomenon of oxidation was also observed when machining at high cutting speed, which resulted in diffusion wear and increase in the crater wear. Based on the relationship between the cutting force and cutting temperature, it can be concluded that these machining outputs are significant in affecting the progression of tool wear rate, and tool wear mechanism in the machining of AISI 4340 alloy steel.

Evaluation of Additive Friction Stir Deposition of AISI 316L For Repairing Surface Material Loss in AISI 4340

Additive technologies provide a means for repair of various failure modes associated with material degradation occurring during use in aggressive environments. Possible repair strategies for AISI 4340 steel using AISI 316L deposited by additive friction stir deposition (AFSD) were evaluated under this research by metallography, microhardness, and wear and mechanical testing. Two repair geometries were investigated: groove-filling and surface cladding. The former represents repair of localized grinding to eliminate cracks, while the latter represents material replacement over a larger area, for example to repair general corrosion or wear. The 316L deposited by AFSD exhibited a refined microstructure with decreased grain size and plastic strain, lower strength, and lower hardness than the as-received feedstock. Wear testing by both two-body abrasion and erosion by particle impingement indicated that the wear resistance of the 316L cladding was as good as, or better than, the substrate 4340 material; however, there was some evidence that the resistance to intergranular corrosion was compromised due to the formation of carbides or sigma phase. In both repair geometries, the microstructure of the substrate beneath the deposited material exhibited heat affected zones that appeared to have austenized during the deposition process, and transformed to martensite or bainite during cooling. This report constitutes an initial evaluation of a novel approach to the repair of structural steel components damaged by microcracking, wear or corrosion.

Tempering Influence on Residual Stresses and Mechanical Properties of AISI 4340 Steel

The present work evaluated the tempering temperature influence on microstructure, mechanical properties and residual stresses of AISI 4340 steel. The residual stresses were measured by X‑ray diffraction (XRD) by the sin²ψ method and compared to magnetic Barkhausen noise (MBN). The residual stresses exhibited high tensile values after quenching, but a small relief was observed in tempering treatments at 300°C and 400°C, which also presented a hardness decrease compared to the as‑quenched condition. XRD and MBN analyses indicated that residual stresses became compressive in tempering performed between 500°C and 650°C. Therefore, compressive residual stresses combined with appropriate hardness and toughness values (35 HRC and 33 J) obtained from 500°C tempering temperature can be used to improve the mechanical properties of AISI 4340 steel components. Additionally, a mathematical model was established to estimate the tempered martensite hardness for different tempering temperature conditions. This model showed high accuracy (R2=0.99) for a holding time of 90 minutes.

Analisa kekuatan pada poros roda depan motor honda blade 110R tahun 2010 dengan material St90 JIS SCM 447 – AISI 4340

<p><em>Saat ini di indonesia sepeda motor merupakan alat tranportasi yang sudah di produksi massal. penggunaan sparepart sepeda motor antara yang merek satu dengan merek yang lainnya sudah umum dilakukan dikarenakan komponen tersebut terkadang sulit didapatkan di pasaran. Entah karena sparepart sepeda motor tersebut tidak lagi diproduksi oleh pabrikan atau memang ada faktor-faktor lain yang mempengaruhinya. Poros adalah salah satu komponen sepeda motor , dimana poros merupakan salah satu bagian yang terpenting dari setiap mesin. Peranan utama sebuah poros adalah untuk mentransmisikan daya dari satu elemen mesin ke bagian elemen mesin lainnya. Daya tersebut dihasilkan oleh gaya tangensial dan momen torsi yang hasil akhirnya adalah daya tersebut akan ditransmisikan kepada elemen lain yang terhubung dengan poros tersebut. Poros roda merupakan salah satu komponen yang saangat penting dari sebuah sepeda motor karena poros berfungsi untuk menopang body, beban kendaraan itu sendiri maupun beban luar pada kendaraan dalam hal ini manusia atau barang muatan pada sepeda motor. Sehingga di perlukan poros yang baik untuk mencapai fungsi dari poros tersebut. Dipenelitian ini akan membahas tentang Poros dengan beban puntir dan lentur yang bertujuan untuk memberikan pengetahuan tentang poros depan, Lebih menambah wawasan pengetahuan dalam bidang otomotif dan Mampu merencanakan secara sistematis elemen-elemen mesin yang ada pada system kerja poros. Perhitungan Beban Luar, Perhitungan Diameter Poros, Jadi hasil dari perhitungan poros bahwa diameter 9.9 mm aman digunakan sesuai dengan standard, dengan diameter poros actual dilapangan yaitu 10 mm</em></p>

Evaluation The Performance Of Cvd And Pvd Coated Carbide Tool In Hard Turning Of Aisi-4340 Steel

The work introduced in this proposal tends to the surface unpleasantness and flank wear during hard turning of AISI 4340 steel (33HRC) utilizing CVD (TiCN/Spasm/Al2O3/TiN) multi-facet covered carbide device and PVD (TiCN/Al2O3) covered carbide device. Three variables (cutting rate, feed and profundity of cut) and three level factorial test plans with Taguchi’s L9OA and factual examination of difference were acted to explore the impact of these cutting boundaries on the apparatus and work piece as far as flank wear, and surface harshness. Additionally the examination of these impacts between previously mentioned sorts of apparatuses was finished. The outcomes show that for surface unpleasantness and flank wear, feed and cutting velocity were measurably huge and profundity of cut had least impact on both surface harshness and flank wear. For surface harshness, feed was more huge followed by cutting velocity for the two sorts of devices, while as, for flank wear cutting pace was more huge followed by feed for the two kinds of instruments. Surface completion was estimated in Ra boundary and a decent surface completion was acquired by PVD covered apparatus at low and medium rates, anyway with the speeding up the CVD covered carbide device showed better surface completion. Flank wear was estimated by utilizing optical magnifying instrument and the outcomes show that more wear happened in PVD covered carbide apparatus when contrasted with CVD covered carbide device under same cutting boundaries and natural conditions. Consequently for better surface completion at low and medium velocities PVD covered carbide apparatus is better and for higher paces, CVD covered carbide device is ideal. For low apparatus wear, CVD covered carbide device is liked.