Experimental and numerical study of chip formation during straight turning of hardened AISI 4340 steel

2005 ◽  
Vol 219 (7) ◽  
pp. 515-524 ◽  
Author(s):  
S Belhadi ◽  
T Mabrouki ◽  
J-F Rigal ◽  
L Boulanouar
Keyword(s):  
Chip Formation ◽  
Numerical Study ◽  
Chip Morphology ◽  
Effect Of Temperature ◽  
Serrated Chip ◽  
Aisi 4340 Steel ◽  
4340 Steel ◽  
Sawtooth Chip ◽  
Coated Carbide ◽  
Aisi 4340

The present paper is a contribution to the investigation of physical phenomena accompanying sawtooth chip formation in the case of hard turning. The study concerns the machining with coated carbide of tempered AISI 4340 steel with a Rockwell C hardness of 47 HRC. The main idea in this paper deals with the establishment of a direct relationship between serrated-chip morphology simultaneously with force component signals derived from acquisition at high frequency and with the width of facets detected on a workpiece machined surface. This experimental work was supported by a numerical simulation based on Abaqus/ Explicit software. Numerical results dealing with effect of temperature evolution on the chip morphology show that the beginning of the sawtooth chip initiation is due to an adiabatic shear at the tool tip with propagation pathway towards the free surface. In addition, computed results have a good corroboration with those obtained experimentally.

Some studies on hard turning of AISI 4340 steel using multilayer coated carbide tool

Measurement ◽  
2012 ◽  
Vol 45 (7) ◽  
pp. 1872-1884 ◽  
Author(s):  
R. Suresh ◽  
S. Basavarajappa ◽  
G.L. Samuel
Keyword(s):  
Hard Turning ◽  
Carbide Tool ◽  
Aisi 4340 Steel ◽  
Coated Carbide Tool ◽  
4340 Steel ◽  
Coated Carbide ◽  
Aisi 4340

Improvement in Surface Quality With Molybdenum Disulphide as Solid Lubricant in Turning AISI 4340 Steel

2010 ◽  
Author(s):  
A. P. S. Gaur ◽  
Sanjay Agarwal
Keyword(s):  
Surface Quality ◽  
Solid Lubricant ◽  
Machining Process ◽  
Tool Geometry ◽  
Molybdenum Disulphide ◽  
Aisi 4340 Steel ◽  
4340 Steel ◽  
Coated Carbide ◽  
Zone Temperature ◽  
Aisi 4340

It is generally considered that the heat produced during the machining process is critical in terms of workpiece quality. Relatively high friction effects in machining cause heat generation that can lead to poor surface quality of a machined part. Coolant and lubrication therefore play decisive roles in machining. Cutting fluids are introduced in the machining zone to improve the tribological characteristics of machining processes and also to dissipate the heat generated, but they are partially effective within a narrow working range. In addition, they also create some techno-environmental problems. Solid lubricant assisted machining is a novel concept to control the machining zone temperature without polluting the environment. Solid lubricant, if employed properly, could control the machining zone temperature effectively by intensive removal of heat from the machining zone. Therefore, the aim of present study is to investigate the effect of molybdenum disulphide as solid lubricant in the zone of machining. Experiments were carried out to investigate the role of solid lubricant such as molybdenum disulphide on surface finish of the product in machining a AISI 4340 steel by coated carbide inserts of different tool geometry under different cutting conditions. Results indicate that the effectiveness of solid lubricant is substantial through the experimental domains.

On the Catastrophic Shear Instability in High-Speed Machining of an AISI 4340 Steel

1982 ◽  
Vol 104 (2) ◽  
pp. 121-131 ◽  
Author(s):  
R. Komanduri ◽  
T. Schroeder ◽  
J. Hazra ◽  
B. F. von Turkovich ◽  
D. G. Flom
Keyword(s):  
Titanium Alloys ◽  
Shear Zone ◽  
Chip Formation ◽  
High Speed ◽  
Shear Bands ◽  
Shear Instability ◽  
Aisi 4340 Steel ◽  
4340 Steel ◽  
Cutting Speeds ◽  
Aisi 4340

An AISI 4340 Steel (325 BHN) was machined at various speeds up to 2500 m/min (8000 SFPM). Longitudinal midsections of the chips were examined metallurgically to delineate the differences in the chip formation characteristics at various speeds. Chips were found to be continuous at 30 to 60 m/min (100 to 200 SFPM) but discontinuous below this speed. Instabilities in the cutting process, leading to different types of cyclic chip formations, were observed at cutting speeds above 60 m/min (200 SFPM). Fully developed catastrophic shear bands separated by large areas (segments) of relatively less deformed material, similar to that when machining titanium alloys, were observed in the chips at cutting speeds above 275 m/min (800 SFPM). The intense shear bands between the segments appeared to have formed subsequent to the localized intense deformation of the segment in the primary shear zone. As the cutting speed increases, the extent of contact between the segments is found to decrease rapidly. At speeds of 1000 m/min (3200 SFPM) and above, due to rapid intense, localized shear between the segments, these segments were found to separate completely as isolated segments instead of being held intact as a long chip. The speed at which this decohesion occurs was found to depend upon the metallurgical state of the steel machined and its hardness. As in the case of machining titanium alloys, the deformation of the chip as it slides on the tool face, i.e., “secondary shear zone,” appeared to be negligible when machining this AISI 4340 steel at high speed. Based on the metallurgical study of the chip and the similarities of machining this material at high speed and that of titanium alloys at normal speed, a cyclic phenomenon in the primary shear zone is identified as the source of instability responsible for the large-scale heterogeneity and a mechanism of chip formation when machining AISI 4340 steel at high speed is proposed.

scholarly journals Experimental investigation on hard turning of AISI 4340 steel using cemented coated carbide insert

2018 ◽  
Vol 314 ◽  
pp. 012004
Author(s):  
J Pradeep Kumar ◽  
K P Kishore ◽  
M Ranjith Kumar ◽  
K R Saran Karthick ◽  
S Vishnu Gowtham
Keyword(s):  
Experimental Investigation ◽  
Hard Turning ◽  
Aisi 4340 Steel ◽  
4340 Steel ◽  
Coated Carbide ◽  
Carbide Insert ◽  
Aisi 4340

Dynamic chip formation of ultrasonic-assisted micro-drilling on AISI 4340 steel

2021 ◽  
Author(s):  
Guangjun Chen ◽  
Jinkai Xu ◽  
Jingdong Wang ◽  
Jiaqi Wang ◽  
Huadong Yu
Keyword(s):  
Chip Formation ◽  
Aisi 4340 Steel ◽  
4340 Steel ◽  
Ultrasonic Assisted ◽  
Micro Drilling ◽  
Aisi 4340
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