Table 2.

Welding input parameters and their levels.

Number	Parameter	Unit	Notation	Low level (−1)	High level (+1)
1	Wire feed rate	m/min	F	7	19
2	Welding voltage	Volt	V	20	30
3	Welding speed	mm/min	S	200	500
4	Travel angle	Degree	A	60	80
5	Tip-to-work distance	mm	D	7	15
6	Shield gas flow rate	Liter/min	G	10	20