Optimization of Cryogenic Process Parameters for the Minimization of Surface Residual Stress in Pure Iron Using Taguchi Design

Table 1

Levels of the control factors.

Control factors	Level 1	Level 2	Level 3
T (K)	193	135	77
t (H)	8	16	24
(K/min)	2	4	6
(K/min)	1.5	1	0.5