This work explores the optimization of automatic flux cored wire welding parameters for crack-free hardfacing. A series of tests was carried out for verifying the influence of current, travel speed, torch angle, oscillation amplitude, dwell time and frequency, contact-tip work distance and pre-heating on crack information. Experimental Statistics were used for planning and analysing the experiments. The result show that pre-heating and oscillation amplitude are the most significant factors: the greater the pre-heating temperature and the narrower the oscillation amplitude, the lesser is the cracking. The relationship between crack occurrence and increase in hardness was explored also. No association was found with the microstructure, despite the influence of some parameters and dilution on the microstructure. It is concluded that it is possible to eliminate cracking in hardfacing with no hardness decrease (optimization equations are proposed). (C) 1997 Elsevier Science S.A.
