Experimental and Numerical Investigation on the Influence of Process Speed on the Blanking Process

2002 ◽  
Vol 124 (2) ◽  
pp. 416-419 ◽  
Author(s):  
A. M. Goijaerts ◽  
L. E. Govaert ◽  
F. P. T. Baaijens

In a previous work a numerical tool was presented which accurately predicted both process force and fracture initiation for blanking of a ferritic stainless steel in various blanking geometries. This approach was based on the finite element method, employing a rate-independent elasto-plastic constitutive model combined with a fracture criterion which accounts for the complete loading history. In the present investigation this work is extended with respect to rate-dependence by employing an elasto-viscoplastic constitutive model in combination with the previously postulated fracture criterion for ferritic stainless steel. Numerical predictions are compared to experimental data over a large range of process speeds. The rate-dependence of the process force is significant and accurately captured by the numerical simulations at speeds ranging from 0.001 to 10 mm/s. Both experiments and numerical simulations show no influence of punch velocity on fracture initiation.

Author(s):  
Prudvi Reddy Paresi ◽  
N. Arunachalam ◽  
Yanshan Lou ◽  
Jeong Whan Yoon

Abstract Numerical modelling of the plastic deformation and fracture during the high speed machining is highly challengeable. Consequently, there is a need for an advanced constitutive model and fracture criterion to make the numerical models more reliable. The aim of the present study is to extend the recent advanced static Lou-Yoon-Huh (LYH) ductile fracture creation to high strain rate and temperature applications such as machining. In the present work, the LYH static fracture creation was extended to machining conditions by introducing strain rate and temperature dependency terms. This extended LYH fracture criterion was calibrated over the wide range of stress triaxialities and different temperatures. Modified Khan- Huang-Liang (KHL) constitutive model along with the variable friction model was employed to predict the flow behaviour of work material during the machining simulation. Damage evolution method was coupled to identify the element deletion point during the machining simulation. Orthogonal machining experiments were carried out for an aerospace grade AA2024-T351 at cutting speeds varying between 100 and 400m/min with the feed rates varying between 0.1 and 0.3mm/rev. To assess the prediction capabilities of extended LYH fracture criterion numerical simulations were also carried out using Johnson-Cook (JC) fracture criterion under all experimental conditions. Specific cutting energy, chip morphology and compression ratio predictions were compared with the experimental data. Numerical predictions with coupled extended LYH criterion showed good agreement with experimental results compared to coupled JC fracture criterion.


Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 678 ◽  
Author(s):  
Yohei Suzuki ◽  
Ming Yang ◽  
Masao Murakawa

An extrusion-type fine blanking with a negative clearance was proposed by the authors instead of standard fine blanking for creating a full-sheared surface in the micro blanking process. In this study, micro blanking experiments and finite element analyses with narrow, zero and negative clearances are carried out for the optimizing the clearance at which a shear cut surface can be finished with a full-sheared surface with the minimized punch load. Fracture criterion, hydrostatic stress and maximum punch stress for the conditions with various clearances are investigated. As a result, it was clarified that the clearance at which the cut surface does not fracture and minimization of the punch load is achieved is gained by the use of clearance −4 μm.


2010 ◽  
Vol 48 (04) ◽  
pp. 297-304 ◽  
Author(s):  
Jong Pan Kong ◽  
Tae Jun Park ◽  
Hye Sung Na ◽  
Jeong Kil Kim ◽  
Sang Ho Uhm ◽  
...  

2010 ◽  
Vol 48 (04) ◽  
pp. 289-296 ◽  
Author(s):  
Myung-Bok Kim ◽  
Sang-Ju Kim ◽  
Bong-Keun Lee ◽  
Xinjian Yuan ◽  
Byoung-Hyun Yoon ◽  
...  

Alloy Digest ◽  
2013 ◽  
Vol 62 (2) ◽  

Abstract ATI 409HP (UNS S40900) ferritic stainless steel was introduced by ATI Allegheny Ludlum to provide improved oxidation and corrosion resistance for automotive exhaust systems in comparison to carbon steel. The alloy was designated "MF-1", indicating its end use: automotive mufflers. The good fabricability of this alloy, combined with its basic corrosion resistance and economy have significantly broadened the utility of ATI 409HP stainless steel. ATI 409HP consists of four grades: UNS S40900, S40910, S40920, and S40930. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, machining, and joining. Filing Code: SS-1135. Producer or source: Allegheny Technologies Inc..


Alloy Digest ◽  
1979 ◽  
Vol 28 (5) ◽  

Abstract SEA-CURE is a ferritic stainless steel designed to provide high resistance to pitting and crevice corrosion in condensers cooled by saline or brackish water. It is used for condenser tubes and has great potential for many other uses. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fatigue. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-364. Producer or source: Trent Tube.


Alloy Digest ◽  
2006 ◽  
Vol 55 (6) ◽  

Abstract AK Steel 441 has good high-temperature strength, an equiaxed microstructure, and good high-temperature oxidation resistance. The alloy is a niobium-bearing ferritic stainless steel. This datasheet provides information on composition, hardness, and tensile properties as well as deformation. It also includes information on high temperature performance and corrosion resistance as well as forming and joining. Filing Code: SS-965. Producer or source: AK Steel.


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