Comparative Analysis on Wiper and Standard Tools in Dry Finish Turning of Martensitic Stainless Steel AISI 420

2013 ◽  
Vol 845 ◽  
pp. 765-769 ◽  
Author(s):  
Guilherme Cortelini Rosa ◽  
André J. Souza ◽  
Flávio J. Lorini

Machining performance consists to associate the optimal process and cutting parameters and maximum material removal rate with the most appropriate tool while controlling the machined surface state. This work verifies the influence of standard and wiper cutting tools on generated surface roughness and residual stress in dry finish turning operation of the martensitic stainless steel AISI 420 in a comparative way. Tests are conducted for different combinations of tool nose geometry, feed rate and depth of cut being analyzed through the Design of Experiments regarding to surface roughness parametersRaandRt. Moreover, the formation of residual stresses in the material (using the technique of X-Ray Diffraction) was evaluated after the machining process for these two cutting geometries and thereafter the result was compared between them. An ANOVA is performed to clarify the influence of cutting parameters on generated surface roughness, which outputs inform that cutting tool geometry is the most influent onRaandRt. It is concluded that analyzed wiper inserts present low performance for low feed rates. Regarding the analysis of the residual stresses it can be stated that for standard and wiper tools the values collected show that for finish turning the compression stresses were found. It can be observed that the greatest amount of compressive stress has been found for the standard tool.

Author(s):  
Abderrahmen Zerti ◽  
Mohamed Athmane Yallese ◽  
Oussama Zerti ◽  
Mourad Nouioua ◽  
Riad Khettabi

The purpose of this experimental work is to study the impact of the machining parameters ( Vc, ap, and f) on the surface roughness criteria ( Ra, Rz, and Rt) as well as on the cutting force components ( Fx, Fy, and Fz), during dry turning of martensitic stainless steel (AISI 420) treated at 59 hardness Rockwell cone. The machining tests were carried out using the coated mixed ceramic cutting-insert (CC6050) according to the Taguchi design (L25). Analysis of the variance (ANOVA) as well as Pareto graphs made it possible to quantify the contributions of ( Vc, ap, and f) on the output parameters. The response surface methodology and the artificial neural networks approach were used for output modeling. Finally, the optimization of the machining parameters was performed using desirability function (DF) minimizing the surface roughness and the cutting forces simultaneously. The results indicated that the roughness is strongly affected by the feed rate ( f) with contributions of (80.71%, 80.26%, and 81.80%) for ( Ra, Rz, and Rt) respectively, and that the depth of cut ( ap) is the factor having the major influence on the cutting forces ( Fx = 53.76%, Fy = 50.79%, and Fz = 65.31%). Furthermore, artificial neural network and response surface methodology models correlate very well with experimental data. However, artificial neural network models show better accuracy. The optimum machining setting for multi-objective optimization is Vc = 80 m/min, f = 0.08 mm/rev and ap = 0.141 mm.


2002 ◽  
Vol 150 (2-3) ◽  
pp. 263-268 ◽  
Author(s):  
I Alphonsa ◽  
A Chainani ◽  
P.M Raole ◽  
B Ganguli ◽  
P.I John

2012 ◽  
Vol 57 (3) ◽  
pp. 799-804 ◽  
Author(s):  
L. Angkurarach ◽  
P. Juijerm

The effects of direct current field on a powder-packed boriding process on a martensitic stainless steel AISI 420 have been investigated at a temperature of 900°C for about 2–6 hr. A powder-packed boriding process without direct current field (conventional powder-packed boriding process, PB) is a reference as compared to the powder-packed boriding process with applied current densities (PB-DC) of 60-170 mA/cm2. The microstructure and the presence of boride layers of PB and PB-DC were characterized using optical microscope and X-ray diffraction (XRD). The hardness values of the boride layer were measured by Vickers microhardness tester. Experimental results show that the direct current filed can enhance the decomposition and chemical reaction in the boriding agent and also drive active free boron ions as well as atoms to diffuse toward the cathode. Therefore, a boron concentration around the specimen at the cathode of PB-DC is higher than that at the anode as well as PB (as a reference). As a consequence, higher boride layer thickness of PB-DC was detected. The double-phase boride layer (FeB and Fe2B) on borided martensitic stainless steel AISI 420 was found both PB and PB-DC. The hardness of the boride layer of about 1800–2000 HV can be observed.


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