INFLUENCE OF OSCILLATION PARAMETERS ON CRACK FORMATION IN AUTOMATIC FE-B HARDFACING

This work explores the optimization of automatic flux cored wire weldi ng 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 di stance and pre-heating on crack information. Experimental Statistics w ere used for planning and analysing the experiments. The result show t hat pre-heating and oscillation amplitude are the most significant fac tors: the greater the pre-heating temperature and the narrower the osc illation amplitude, the lesser is the cracking. The relationship betwe en crack occurrence and increase in hardness was explored also. No ass ociation was found with the microstructure, despite the influence of s ome parameters and dilution on the microstructure. It is concluded tha t it is possible to eliminate cracking in hardfacing with no hardness decrease (optimization equations are proposed). (C) 1997 Elsevier Scie nce S.A.