Optimization and Prediction of Ultimate Tensile Strength in Metal Active Gas Welding

Table 4

Estimated effects and coefficients for UTS (coded units).

Term	Effect	Coefficient	-statistic	value
Constant		248.69	80.45	<0.001
Wire feed rate,	210.751	105.38	34.09	<0.001
Welding voltage,	27.12	13.56	4.39	<0.001
Welding speed,	−68.13	−34.06	−11.02	<0.001
Travel angle,	22.00	11.00	3.56	0.002
Tip-to-work distance,	−99.50	−49.75	−16.09	<0.001
Shield gas flow rate,	−0.25	−0.13	−0.04	0.968
	116.00	58.00	18.76	<0.001
	−22.00	−11.00	−3.56	0.002
	−16.63	−8.31	−2.69	0.015
	−43.63	−21.81	−7.06	<0.001
	−16.00	−8.00	−2.59	0.018
	21.12	10.56	3.42	0.003

= 17.4857 = 99.07%   (adj.) = 98.48%, coefficient standard error = 3.1.