Optimization of Surface Quality and Power Consumption in Machining Hardened AISI 4340 Steel

Table 6

Surface roughness and cutting power ANOVA results.

Variance source	Degrees of freedom (DoF)	Sum of squares (SS)	Mean squares (MS)	F ratio	P-value	Contribution rate (%)
Ra
Tool type	1	0.3511	0.35112	3.81	0.075	4.73
Cutting speed	2	5.2347	2.61737	28.38	≤0.001	70.53
Feed rate	2	0.7286	0.36430	3.95	0.048	9.82
Error	12	1.1069	0.09224			14.92
Total	17	7.4213				100
Cp
Tool type	1	10082	10082	18.69	≤0.001	3.32
Cutting speed	2	284648	142324	263.88	≤0.001	93.61
Feed rate	2	2861	1431	2.65	0.111	0.94
Error	12	6472	539			2.13
Total	17	304064				100