Taguchi Method

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Taguchi Method

• Applied to a Heat Treatment Process for Steel
• Sean Gant
• Jay Lee

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EXAMPLE Heat treatment process used to harden
steel components
Level 1 Level 2
Temperature 760 900 oC
Quenching Rate 35 140 oC/s
Cooling Time 1 300 s
Carbon Content 1 6 wt C
CO2 Concentration 5 20
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OBJECTIVE Determine which process parameters have
the greatest impact on the hardness of the steel
components
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ARRAY SELECTION 5 process parameters 2 Levels
L8 Array
Experiment P1 P2 P3 P4 P5 P6 P7
1 1 1 1 1 1 1 1
2 1 1 1 2 2 2 2
3 1 2 2 1 1 2 2
4 1 2 2 2 2 1 1
5 2 1 2 1 2 1 2
6 2 1 2 2 1 2 1
7 2 2 1 1 2 2 1
8 2 2 1 2 1 1 2
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Experiment Carbon Content (wt C) Quenching Rate (oC/s) Cooling Time (s) CO2 Concentration (mol ) Temperature (oC)
1 1 35 1 5 760
2 1 35 1 20 900
3 1 140 300 5 760
4 1 140 300 20 900
5 6 35 300 5 900
6 6 35 300 20 760
7 6 140 1 5 900
8 6 140 1 20 760
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RUNNING EXPERIMENTS Run 4 trials for each
experiment
Experiment T1 T2 T3 T4
1 68.00 61.41 66.33 97.07
2 69.84 64.76 86.07 51.67
3 74.36 61.30 94.57 96.81
4 71.71 58.42 77.23 60.05
5 91.27 90.89 84.54 63.72
6 54.39 73.01 50.10 79.62
7 64.65 91.51 72.68 84.33
8 60.31 60.69 76.73 74.97
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Taguchi Equations
Sample Calculations for first experiment






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Experiment P1 P2 P3 P4 P5 SN
1 1 1 1 1 1 13.07
2 1 1 1 2 2 13.55
3 1 2 2 1 1 13.61
4 1 2 2 2 2 17.29
5 2 1 2 1 2 16.06
6 2 1 2 2 1 13.02
7 2 2 1 1 2 16.30
8 2 2 1 2 1 17.67
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Level P1 P2 P3 P4 P5
1 14.38 13.93 15.15 14.76 14.34
2 15.76 16.22 15.00 15.39 15.80
? 1.38 2.29 0.15 0.63 1.46

• Table of the average SN value for each factor
• ? Max Min
• The Parameter with the highest value of delta is
  the most important parameter to investigate (P2
  Quenching Rate)