Available online at www.sciencedirect.com
ScienceDirect Materials Today: Proceedings 4 (2017) 2114–2118
www.materialstoday.com/proceedings
5th International Conference of Materials Processing and Characterization (ICMPC 2016)
Analysis of Forces during Hard Turning of AISI 52100 Steel Using Taguchi Method B. Ravi Sankar*, P. Umamaheswar rao
Department of Mechanical Engineering, Bapatla Engineering College, Bapatla, A.P, India
Abstract In the present work an attempt has been made to investigate the effect of the turning parameters on the forces developed during hard turning of AISI 52100 bearing steel with PCBN cutting tools. The experiments are devised using Taguchi L27 orthogonal array and analysis is carried out using MINITAB 14 software. The effect of individual parameters is discussed with main effects plot. The contribution of parameters on the response is estimated by conducting ANOVA. From the results it is observed that influencing parameters are in the order of nose radius, depth of cut, speed and feed. ©2017 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of Conference Committee Members of 5th International Conference of Materials Processing and Characterization (ICMPC 2016). Keywords:Hard turing; AISI 52100 steel; PCBN tool; L27 orthogonal array; ANOVA
1. Introduction Turning of High-hardness materials (above 45 HRC) termed as hard turning. It is proved to be the possible alternative for grinding and was renowned by automotive industry [1]. It is reported that if hard turning is used to fabricate complex parts, manufacturing costs could be reduced by up to 30 times [2-3]. The manufacturing of automotive components, gear, bearing, tool and die etc widely uses AISI 52100 steel. As the tool in turning was to be harder than work piece, hence the main tool materials that are used for hard turning include sintered carbides, ceramics (e.g. Al2O3 or Si3N4 etc.), and extra-hard materials (e.g. PCD, PCBN etc.). In general, turning process was strongly affected by the forces generated with respect to the tool geometry and surface quality. The cutting forces contribute a lot on the performance of during turning via the machinability of the work piece, the process of chip formation, chatter, and tool wear [4]. The cutting forces increase drastically when machining materials with hardness higher than about 45 HRC [5]. The cutting force was strongly affected by depth of cut rather than speed and feed for AISI 52100 steel [6-10]. * Corresponding author. Tel.:+919292906720; E-mail address:
[email protected]
2214-7853©2017 Elsevier Ltd. All rights reserved. Selection and peer-review under responsibility of Conference Committee Members of 5th International Conference of Materials Processing and Characterization (ICMPC 2016).
B Ravi sankar/ Materials Today: Proceedings 4 (2017) 2114–2118
2115
Thiele and Melkote [11] investigated the effects of tool edge geometry of CBN tools and work piece hardness on the surface roughness and cutting forces in the finish hard turning of AISI 52100 steel. Their study showed that the tool edge geometry had significant effect on higher forces in the axial, radial and tangential directions. Kurt and Seker [12] investigated the effects of chamfer angle on the cutting forces and the stresses on the PCBN cutting tools in finishing hard turning of AISI 52100 bearing steel. They reported that the chamfer angles have a great influence on the passive cutting forces. Several past studies on AISI 52100 steel were conducted to study the influence of the parameters such speed, feed and depth of cut and reported that depth of cut was the most significant factor contributing forces developed. Some other studies investigated the influence tool edge geometry namely chamfer angle and found it had a great influence on the cutting forces. Hence in the present work it is aimed to study the influence of parameters such as speed, feed and depth of cut along with nose radius. 2. Experimental Procedure The work material is AISI52100 alloy steel which has its major application in bearings. Bars of AISI 52100 steel, 32 mm in diameter and 350 mm in length are used in this study. The hardness after heat treatment is obtained as 58.0±0.5 HRC. The cutting inserts used are PCBN tool inserts of different nose radius 0.4, 0.8, 1.2 mm (CNMG 120404, CNMG 120408, and CNMG 120412). Rigid, high power precision lathe equipped with specially designed experimental setup is used for experimentation. For increasing rigidity of machining system, work piece material is held between chuck (three jaws) and tailstock (revolving center) and the turning of work piece in dry turning conditions are conducted on centre lathe with variable speed & feed drive (Make: kirloskar; Model: turnmaster-35). The cutting forces are measured using Kistler multi component dynamometer (type: 9257B) mounted on specially designed fixture. The charge generated at the dynamometer is amplified using three-charge amplifier (charge amplifier: 5070A). The input sensitivities of the three-charge amplifiers are set corresponding to the output sensitivity of the force dynamometer in the x, y and z directions. The outputs are tangential force (Fz), feed force (Fx) and thrust force (Fy) on the respective charge amplifier generated and stored in computer using Lab VIEW software for further analysis. The experimental setup is shown in Fig 1. Based on [13-14] and tool manufacturer recommendations, feasible range of cutting parameters for a given cutting tool–work piece system are selected as shown in the table 1. Taguchi L27 orthogonal array is adopted for reducing the number of experiments.
S.No
Parameter
Notation
Unit
Levels -1
0
1
1.
Speed, N
A
rpm
400
650
2.
Feed, F
B
mm/rev
0.04
0.06
900 0.08
3.
Depth of cut
C
mm
0.4
0.6
0.8
4.
Tool nose radius
D
mm
0.4
0.8
1.2
Table 1. Factors and their levels
2116
B Ravi sankar/ Materials Today: Proceedings 4 (2017) 2114–2118
AISI 52100 alloy steel
Dynamometer
Fig 1. Experimental Setup
3. Results In the present work hard turning is carried out on AISI52100 steel using PCBN cutting tool. Taguchi L27 orthogonal array is adopted for experimentation and the experimental matrix along with results is shown in Table. 2. The analysis is performed using MINITAB 14 software. The effect of various parameters on forces is discussed with main effects plot and ANOVA. Fig. 2. Shows the main effects plot for force with respect to speed, feed, depth of cut and nose radius. From the plot it can be understood that the force is increasing with all the parameters, however the increment is varying for each parameter. To identify the significance of the input parameters on the response ANOVA is performed and shown in table. 3 From ANOVA table discloses that nose radius is the major contributing factor followed by depth of cut. However, the effect of speed and feed is nominal compared with nose radius and depth of cut.
B Ravi sankar/ Materials Today: Proceedings 4 (2017) 2114–2118
2117
Table 2. Experimental design matrix with results Speed, rpm
Feed mm/rev
1.
400
0.04
0.4
2.
400
0.06
3.
400
0.08
4.
400
5.
S. No
Depth of Cut, Nose radius mm mm
force
4
125.85
0.6
8
436.65
0.8
12
580.47
0.04
0.6
12
483.91
400
0.06
0.8
4
393.79
6.
400
0.08
0.4
8
324.7
7.
400
0.04
0.8
8
476.43
8.
400
0.06
0.4
12
507.01
9.
400
0.08
0.6
4
397.46
10.
650
0.04
0.4
4
240.26
11.
650
0.06
0.6
8
416.75
12.
650
0.08
0.8
12
670.97
13.
650
0.04
0.6
12
537.16
14.
650
0.06
0.8
4
622.44
15.
650
0.08
0.4
8
462.69
16.
650
0.04
0.8
8
424.45
17.
650
0.06
0.4
12
483.78
18.
650
0.08
0.6
4
383.76
19.
900
0.04
0.4
4
349.88
20.
900
0.06
0.6
8
489.93
21.
900
0.08
0.8
12
860.34
22.
900
0.04
0.6
12
572.86
23.
900
0.06
0.8
4
453.71
24.
900
0.08
0.4
8
392.77
25.
900
0.04
0.8
8
459.98
26.
900
0.06
0.4
12
557.21
27.
900
0.08
0.6
4
528.4
Table 3. ANOVA Factor
DoF 2
Sum of Squares 48828.478
Speed Feed
2
Depth of cut Nose radius
Variance 24414.239
Pure sum of squares 40144.6
% 8.12
52414.168
26207.084
43730.36
8.8
2
125514.69
62757.344
116830.89
23.64
2
189138.12
94569.059
180454.38
36.52
2118
B Ravi sankar/ Materials Today: Proceedings 4 (2017) 2114–2118
Fig 2. Main effects plot
4. Conclusions The present work concerns an experimental and analysis of force during hard turning with CBN tool of AISI 52100 bearing steel. The no. of experiments was shortened using Taguchi L27 orthogonal array to obtain the performance characteristics. The effect of input parameters was discussed with main effects plot and the contribution of individual parameters was estimated through ANOVA. The following conclusions were made from the results obtained: 1. From the main effects plot it is clear that the force is increasing with all the parameters, however the increment is varying with the individual parameters. 2. Through ANOVA, the percentage of contribution to the turning process, in sequence, is the nose radius, depth of cut, speed and feed. Hence, the nose radius is the most significant controlled factor for the hard turning operation when force is considered. References [1] Davim, J. P., Machining of hard materials, Springer-Verlag, London, 2011. [2] Huang Y, Chou YK, Liang SY International Journal of Advanced Manufacturing Technology 35 (2007) 443–453. [3] Aouici H, Yallese MA, Chaoui K, Mabrouki T, Rigal JF (2012). Measurement 45 (2012) 344–353. [4] Shaw, M.C., Metal Cutting Principles, Oxford Press, 1984. [5] Awadhesh Pal, S.K. Choudhury,Satish Chinchanikar, Procedia Materials Science. 6 (2014) 80 – 91. [6] Khaider Bouacha, Mohamed Athmane Yallese, Samir Khamel, SalimBelhadi., International Journal of Refractory Metals and Hard Materials. 45 (2014) 160–178. [7] Gaurav Bartaryaa, S.K.Choudhury, Procedia CIRP 1 (2012) 651– 656. [8] Gaurav Bartarya, Sounak K Choudhury, Proc IMechE Part B: Journal of Engineering Manufacture. 228 (9)(2014) 1068–1080. [9] Khaider Bouacha, Mohamed Athmane Yallese, Tarek Mabrouki, Jean-François Rigal c, International Journal of Refractory Metals & Hard Materials. 28 (2010) 349–361. [10] Suha K. Shihab, Zahid A . Khan, Aasmohammad, Arshad Noor Siddiquee, Advanced Materials Manufacturing & Characterization. 3(1) (2013) 27-35. [11] Thiele, J. D., Melkote, S. N. Journal of Materials Processing Technology. 94 (1999) 216– 226. [12] Kurt, A., Seker, U. Materials and Design. 26 (2005) 351–356. [13] Lin, Z.-C., Chen, D-Y., Journal of Materials Processing Technology. 49 (1995) 149–164. [14] Chen, W., International Journal of Machine Tools & Manufacture. 40 (2000) 455–466.