Interaction of 18Cr-10Ni stainless steel with liquid aluminium

• Published in: Journal of materials science Vol. 25; no. 8; pp. 3615 - 3633
• Main Author: DYBKOV, V. I
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer 01.08.1990
• Subjects: Applied sciences; Corrosion; Corrosion environments; Exact sciences and technology; Metals. Metallurgy; Welding; Mechanical property; Intermetallic compound; Surface layer; Surface film; Aluminium; Experimental study; Dissolution; Layer thickness; Corrosion product; Welded joint; Stainless steel; Mechanical characteristic; Iron Aluminides; Kinetics; Molten metal corrosion
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/BF00575397

The welding of Al to stainless steel meets serious difficulties, because these two materials represent one of the numerous examples of the so-called incompatible combinations. Therefore, the transition joints are often used in practice to connect dissimilar metals. The dissolution of an 18Cr--10Ni stainless steel in liquid Al at 700-850 deg C was found by the rotating disc technique to be non-selective and diffusion controlled. Experimentally determined values of the parameters characterizing the dissolution run are presented. In the case of saturated Al melts two intermetallic layers were found to form between the steel and the melt material at 700 deg C. The compact layer adjacent to the steel surface is probably a solid solution based upon the Fe sub 2 Al sub 5 compound. Its thickness, x, tends with increasing time to the limiting value x sub max = 10 mu m. The porous layer adjacent to the melt material is probably a solid solution based upon the FeAl sub 3 compound. After a certain period of non-linear growth its thickness, y, increases with time, t, according to the linear law: y = 1 x 10 exp --8 t + 6 x 10 exp --6 m. The time dependence of the total thickness of both layers is well described in terms of the "paralinear" kinetics. In the case of undersaturated Al melts the formation of a single-phase intermetallic layer, 3-11 mu m thick, was observed at 700 deg C for 100-600 s. The steel-to-Al transition joints with good mechanical properties were made by interaction of a solid steel material with liquid Al. Graphs, Photomicrographs. 36 ref.--AA