Effect of the Cryogenically Treated Copper Nozzle Used in Plasma Arc Machining of S235 Steel

Table 8

Grey relational analysis for cryogenic treated nozzle machining.

Trial runs	SN ratio		Normalized value		Deviation sequence		Grey relational coefficient		Grey grade	Rank
	SR	Kf	SR	Kf	SR	Kf	SR	Kf
	(µm)	(mm)	(µm)	(mm)	(µm)	(mm)	(µm)	(mm)
1	−0.2988	−0.9533	0.0497	0.7371	0.9503	0.2629	0.3448	0.6554	1.0002	14
2	−0.6604	−2.4312	0.0000	0.4400	1.0000	0.5600	0.3333	0.4717	0.8050	25
3	0.3555	−3.4637	0.1397	0.2325	0.8603	0.7675	0.3676	0.3945	0.7620	27
4	0.9732	−1.8467	0.2246	0.5575	0.7754	0.4425	0.3920	0.5305	0.9225	19
5	1.5082	−2.8089	0.2981	0.3641	0.7019	0.6359	0.4160	0.4402	0.8562	24
6	2.0816	−4.6202	0.3770	0.0000	0.6230	1.0000	0.4452	0.3333	0.7786	26
7	2.5499	−2.4659	0.4413	0.4330	0.5587	0.5670	0.4723	0.4686	0.9409	17
8	3.2520	−3.1992	0.5379	0.2857	0.4621	0.7143	0.5197	0.4117	0.9314	18
9	4.0077	−4.5490	0.6417	0.0143	0.3583	0.9857	0.5826	0.3365	0.9191	20
10	−0.2483	−0.2424	0.0567	0.8800	0.9433	0.1200	0.3464	0.8065	1.1529	8
11	0.3845	−1.7065	0.1436	0.5857	0.8564	0.4143	0.3686	0.5469	0.9155	21
12	1.9382	−2.9560	0.3572	0.3345	0.6428	0.6655	0.4375	0.4290	0.8666	23
13	1.8267	−0.7724	0.3419	0.7735	0.6581	0.2265	0.4317	0.6882	1.1199	11
14	2.4043	−2.1442	0.4213	0.4977	0.5787	0.5023	0.4635	0.4989	0.9624	15
15	3.2230	−3.4771	0.5339	0.2298	0.4661	0.7702	0.5175	0.3936	0.9112	22
16	3.9541	−1.7981	0.6344	0.5673	0.3656	0.4327	0.5776	0.5361	1.1137	12
17	4.2792	−2.9412	0.6791	0.3375	0.3209	0.6625	0.6091	0.4301	1.0392	13
18	5.4167	−3.5795	0.8354	0.2092	0.1646	0.7908	0.7524	0.3874	1.1397	9
19	0.4090	0.3546	0.1470	1.0000	0.8530	0.0000	0.3696	1.0000	1.3696	4
20	1.4116	−0.1720	0.2849	0.8942	0.7151	0.1058	0.4115	0.8253	1.2368	7
21	2.5615	−2.4220	0.4429	0.4419	0.5571	0.5581	0.4730	0.4725	0.9455	16
22	2.9382	0.2646	0.4947	0.9819	0.5053	0.0181	0.4974	0.9651	1.4625	2
23	4.5389	−0.9844	0.7148	0.7309	0.2852	0.2691	0.6368	0.6501	1.2868	6
24	4.1582	−1.8052	0.6624	0.5659	0.3376	0.4341	0.5970	0.5353	1.1322	10
25	4.7916	−0.6419	0.7495	0.7997	0.2505	0.2003	0.6662	0.7140	1.3802	3
26	6.6137	−2.0074	1.0000	0.5252	0.0000	0.4748	1.0000	0.5129	1.5129	1
27	6.1607	−2.6067	0.9377	0.4047	0.0623	0.5953	0.8893	0.4565	1.3458	5