1999 ◽  
Author(s):  
Viktor P. Astakhov ◽  
A. A. Komarovskiy

Abstract Everyday practice of cutting process planning requires reliable cutting force estimates, which currently can be obtained only from process-dependent machinability databases. The greatest obstacle to developing a more basic, efficient approach is a lack of understanding of material behavior under unique deformation conditions of cutting. The metal cutting process has been defined by the authors earlier as the purposeful fracture of workpiece material and, therefore, a new way to minimize the energy consumption per unit volume of the layer to be removed in cutting should be revealed in order to predict metal cutting performance. Unfortunately, the traditional mechanical metallurgy has too little to be used for such a purpose. This paper deals with practical applications of the equation of state of a solid to the metal cutting process. It is shown theoretically and proven experimentally that the energy consumed in cutting can be effectively controlled by applying external force fields to the workpiece.


Wear ◽  
2014 ◽  
Vol 311 (1-2) ◽  
pp. 21-30 ◽  
Author(s):  
Johannes Kümmel ◽  
Jens Gibmeier ◽  
Erich Müller ◽  
Reinhard Schneider ◽  
Volker Schulze ◽  
...  

1999 ◽  
Author(s):  
Armen L. Airikyan

Abstract Everyday practice of cutting process planning requires reliable chipbreacking and this is particularly true when machining difficult-ti-machine materials as austenitic stainless steels. The use of pressed-groove type of chipbreakers prove to provide a partly solution of the problem since their utilization unavoidably leads to increasing cutting force and chipping of the cutting edge. The use of clapped-on chipbreaker seems to solve these problems. However new design and application problem arise. This paper deals with the analysis of these problema and offers a methodology for it resolving. As a result, a new type of a clamped-on chipbreaker has been developed.


2014 ◽  
Author(s):  
Jerald E. Jones ◽  
Valerie L. Rhoades ◽  
Mark D. Mann ◽  
Todd Holverson

A new cutting process, a hybrid system, uses induction heating to heat the metal ahead of the plasma cutting torch. The process has demonstrated the ability to plasma cut steel parts at speeds of up to 4X the speed of the plasma torch without the induction heating. Although the total heat input per unit time is greater, because of the increase in speed, the heat which is conducted into the cut pieces is less. This causes less potential metallurgical damage, less potential distortion, and reduced coating damage and reduced emissions during cutting, in comparison to the plasma cutting process without the induction heating. The initial development was primarily for use in cutting nuclear submarine and aircraft carrier hulls, for scrapping after decommissioning. The process has been demonstrated cutting steel plates and can be used in ship production as well. The primary motivation of the SBIR project was to reduce the heating of the cut pieces, in order to reduce the particulate matter (PM) emissions which occur when coated ship hull material is cut. An induction coil is positioned in front of the plasma cutting torch, to bring the material to an elevated temperature of at least 1600° F, before the plasma is applied to the metal surface. Induction heating testing has shown that the 35 kW induction system can maintain the 1600° F surface temperature at travel speeds of above 220 inches per minute on steel as thick as 3 inches. Once the steel is at that temperature an air plasma torch can cut the metal much faster than cutting cold steel.


2013 ◽  
Vol 274 ◽  
pp. 249-252
Author(s):  
Zhi Xin Wang ◽  
Yong Kui Han ◽  
Yong Qiu Chen

Many metal-manufacturing industries include oxyfuel gas cutting among their manufacturing processes because cutting was often used in metal-cutting processes, specifically in the large castings and forgings and the fabrication of pressure vessels. The oxyfuel gas cutting process uses controlled chemical reactions to remove preheated metal by rapid oxidation in a stream of pure oxygen. Previous research has demonstrated microstructure in heat-affected zone varied depending on the gas used for the combustion as well as the cutting speed (Vc) used during the process. In this research, 34CrNiMo6 steel of 900 mm in thickness and 45 carbon steel of 450 mm in thickness were cut using an oxygen-propane flame cutting process. Then, macroscopic morphology and microstructure test were done to analyze the influence of the thickness of cutting cross-section. The results showed, in general, the width of heat-affected zone increased with the thickness of cutting cross-section. Also, it was demonstrated that heat-affected zone in the bottom and top section was wider than others.


Author(s):  
Zheng-Yan Yang ◽  
Xiao-Ming Zhang ◽  
Guang-Chao Nie ◽  
Dong Zhang ◽  
Han Ding

Abstract This study proposes a comprehensive experiment-based method to determine stress field and slip lines in metal cutting process. The chip geometry and workpiece's strain and strain rate fields are determined using an in-situ imaging technique. The two-dimensional (2D) heat transfer problem for the steady-state cutting process is solved to derive the cutting temperature, and the flow stresses of work material in the main deformation zone are calculated based on the plasticity theory. Furthermore, the stress field is comprehensively determined to satisfy the stress equilibrium, friction law along the tool-chip interface, and traction-free boundary condition along the uncut chip surface. In addition, slip lines in the main deformation zone are derived according to the direction of maximum shear stress without the assumption of perfect rigid-plastic material. The proposed method is validated by comparing the cutting forces calculated based on the obtained stress field with the experimentally measurements.


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