Influence Parameters on Nitriding Process of Ferromanganese Alloy

Table 3

Analysis of variances (average effect, sum of square, degree of freedom, mean square, and magnitude effect).

Source of variance	Average effect	Sum of square (SS)	Degree of freedom	Mean square (MS)	(magnitude effect)
A (temperature)	1.995	31.8402	1	31.8402	15119.9
B (time)	0.93	6.9192	1	6.9192	3285.708
AB	0.25	0.5	1	0.5	237.4341
C (nitrogen pressure)	1.6275	21.19005	1	21.19005	10062.48
AC	1.2775	13.05605	1	13.05605	6199.903
BC	0.2225	0.39605	1	0.39605	188.0715
ABC	0.2025	0.32805	1	0.32805	155.7805
D (carbon content)		66.93245	1	66.93245	31784.09
AD		17.22845	1	17.22845	8181.243
BD		4.00445	1	4.00445	1901.586
ABD		0.21125	1	0.21125	100.3159
CD		14.7968	1	14.7968	7026.53
ACD		11.2338	1	11.2338	5334.574
BCD		0.3698	1	0.3698	175.6063
ABCD		0.3528	1	0.3528	167.5335
Error		0.033694	16	0.002106
Total		189.3931	31