Turning of hardened AISI 4340 steel using coated carbide tool

Purpose The purpose of this study is to investigate wear mechanisms of a multi-layered TiAlN/AlCrN-coated carbide tool during the milling of AISI 4340 steel under cryogenic machining. Design/methodology/approach The wear progression was measured using a toolmaker microscope and an optical microscope. Later, a field emission scanning electron microscope and energy-dispersive X-ray analysis were used to investigate the wear mechanisms in detail. Findings A comprehensive analysis revealed that the main causes of tool wear mechanisms were abrasion and adhesion wear on the flank face. Originality/value The investigations presented in this paper may be used by the machining industry to prolong the tool life at higher cutting speed by the application of liquid nitrogen.

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

Proceedings of the Institution of Mechanical Engineers Part B Journal of Engineering Manufacture ◽

10.1243/095440505x32445 ◽

2005 ◽

Vol 219 (7) ◽

pp. 515-524 ◽

Cited By ~ 41

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.

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

Volume 3: Design and Manufacturing, Parts A and B ◽

10.1115/imece2010-37367 ◽

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.

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