Influence of Molybdenum Nanopowder Concentration on Welded Joint Microstructure

Abstract

The paper outlines experimental results of structure formation in welded joints by means of concentration change of molybdenum nanostructured powders in shielding gas. Molybdenum nanostructured powders are arc welded in a liquid welding pool by consumable electrode in argon. It was found out that different powder concentration forms different microstructure of deposited metal.

Effect of Protective Coatings in Welded Constructions on Welding Stability and Electrode Metal Transfer into a Weld Pool in MMA

“…Oscillograms of current in a welding circuit, voltage between an electrode and an item, recorded when MMA with protective coatings (Figure 2) were processed statistically and presented in Table 1. As seen in Table 1, there is 5-11% increase in time of a droplet transfer and 10-12 % rise of cycle duration (period of its formation and transfer), it suggests that electrode metal is transferred in bigger drops [9][10][11][12][13][14][15][16][17][18]. This regularity is possible since protective coatings deposited on edges to be welded form a film, which is a layer between an electrode and an item, being important for welding stability.…”