Machining-induced grain refinement of AISI 4340 alloy steel under dry and cryogenic conditions

Raof, Natasha A.; Ghani, Jaharah A.; Haron, Che Hassan Che

doi:10.1016/j.jmrt.2019.07.045

Cited by 34 publications

(12 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…X-ray phase analysis conducted on machined samples showed that the peaks had a lower relative intensity compared to the as-received samples. The same pattern had also been obtained by other researchers [9,43]. Figure 7 shows the X-ray spectra of the samples before and after machining at the various planes of (110), (101), and (200).…”

Section: Resultssupporting

confidence: 79%

See 1 more Smart Citation

Cryogenic milling and formation of nanostructured machined surface of AISI 4340

Muhamad

Ghani

Haron

et al. 2020

Nanotechnology Reviews

Self Cite

View full text Add to dashboard Cite

Hardened layers are commonly required for automotive components after their production using a machining process in order to enhance the service life of these components. This study investigates the possibility of producing a nanostructured machined surface which can increase the hardness of the machined surface by varying the machining parameters under cryogenic conditions in end milling of AISI 4340. The end milling experiments were performed using multi-layered TiAlN- and AlCrN-coated carbide. Prior to the experiment, a finite element method (FEM) was used to simulate the cutting temperature generated and it had been found that at cutting speed of 200–300 m/min, feed rate of 0.15–0.3 mm/tooth, axial depth of cut of 0.3–0.5 mm, and radial depth of cut of 0.2–0.35 mm, the temperature generated can be sufficiently high to cause austenitic transformation. A field emission scanning electron microscope (FESEM) equipped with angle selective backscattered (AsB) detection analysis was used to investigate the microstructure and machined-affected layers of the machined surfaces. The crystallographic orientation/phase change and nano-hardness were analysed through X-ray diffraction (XRD) and a nano-hardness testing machine. The results showed that the cryogenic machining had significantly affected the surface integrity characteristics of the AISI 4340 alloy due to refined microstructure, favourable phase structure, and higher hardness near the surface layer. The results of this study may be useful in providing an insight into a potential technological shift from conventional surface case hardening processes to the present technique.

show abstract

Section: Resultssupporting

confidence: 79%

“…Hardness changes at the machined surface occurred due to the formation of ultrafine white globular particles. Higher density and more homogeneous ultrafine white globular particles in cryogenically machined surfaces are associated with carbide precipitates, which substantially contributed to the higher hardness [9].…”

Section: Introductionmentioning

confidence: 99%

Cryogenic milling and formation of nanostructured machined surface of AISI 4340

Muhamad

Ghani

Haron

et al. 2020

Nanotechnology Reviews

Self Cite

View full text Add to dashboard Cite

show abstract

“…The average of these values was then determined for each force component (F x , F y and F z ). Previous studies by Muhamad [30] highlighted machining parameters associated with cutting force during cryogenic LN2 machining. Cryogenic milling with low cutting temperatures had successfully reduced the cutting force.…”

Section: Effects Of Force and Cutting Temperature On Cutting Tool Wearmentioning

confidence: 99%

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

et al. 2022

Self Cite

View full text Add to dashboard Cite

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.

show abstract

“…It enhances ductility, strength, toughness, fatigue life, and corrosion resistance without changing chemical composition. It causes grain refinement which reduces the hardness of the material and enhances the machinability of materials [ 6 , 7 ]. Annealing of AISI 4140 steel changes its microstructure by inducing a near-Masing-type effect at higher and lower strain amplitude which increases their ductility, plastic energy, and low-cycle fatigue strength [ 8 , 9 ].…”

Section: Introductionmentioning

confidence: 99%

“…They reported that (a) coated cermet tool produced a higher chip temperature and more flank wear compared to the coated carbide tool, and (b) the coated carbide tool resulted in more surface finish compared to the coated cermet tool. Raof et al [ 6 ] performed the machining of quenched followed by tempered HSLA steel under dry and wet environments using the coated carbide insert. They revealed that wet turning causes a reduction in temperature at the machining zone, thus resulting in improvement in surface quality.…”

Section: Introductionmentioning

confidence: 99%

Investigation on the Performance of Coated Carbide Tool during Dry Turning of AISI 4340 Alloy Steel

et al. 2023

View full text Add to dashboard Cite

The machinability of materials is highly affected by their hardness, and it affects power consumption, cutting tool life as well as surface quality while machining the component. This work deals with machining of annealed AISI 4340 alloy steel using a coated carbide tool under a dry environment. The microhardness of annealed and non-annealed workpieces was compared and a significant reduction was found in the microhardness of annealed samples. Microstructure examination of the annealed sample revealed the formation of coarse pearlite which indicated a reduction of hardness and improved ductility. A commercially CVD multilayer (TiN/TiCN/Al2O3/ZrCN) coated cemented carbide cutting tool was employed for turning quenched and tempered structural AISI 4340 alloy steel by varying machining speed, rate of feed, and depth of cut to evaluate the surface quality, machining forces, flank wear, and chip morphology. According to the findings of experiments, the feed rate possesses a high impact on surface finish, followed by cutting speed. The prominent shape of the serrated saw tooth chip was noticed at a higher cutting speed. Machined surface finish and cutting forces during turning is a function of the wear profile of the coated carbide insert. This study proves that annealing is a low-cost and economical process to enhance the machinability of alloy steel.

show abstract

Machining-induced grain refinement of AISI 4340 alloy steel under dry and cryogenic conditions

Cited by 34 publications

References 20 publications

Cryogenic milling and formation of nanostructured machined surface of AISI 4340

Cryogenic milling and formation of nanostructured machined surface of AISI 4340

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

Investigation on the Performance of Coated Carbide Tool during Dry Turning of AISI 4340 Alloy Steel

Contact Info

Product

Resources

About