Regarding the presence of magnetism at the weld area after stainless steel welding

Welds of austenitic steel generally contain a certain amount of ferrite to prevent welding cracks.

In other words, the welding material contains ferrite. Is it related to the melting that occurs during welding?

It doesn’t matter much; generally, austenitic welding materials contain a certain amount of ferrite.

But when I tested the welding material with a magnet, it had no magnetic property; however, once it was melted to form a weld, it acquired magnetic properties. This is what I find most confusing

Search Baidu for the mechanism of ferrite formation in austenitic stainless steel welds

This post was last edited by nj1952 on 2017-8-5 at 11:20. I agree with the answers given by those above; for more details, refer to the Schaeffler diagram. The Schaeffler diagram is a graphical representation of the quantitative relationship between the chemical composition and microstructure of stainless steel weld metal. It is a microstructure diagram drawn by Schaeffler based on empirical statistics of the weld microstructure from manual arc welding of stainless steel (1949). Using this diagram, the effective methods for deposition can be determined. In the stainless steel microstructure diagram drawn by Schaeffler, the vertical axis is represented by Nieq (nickel equivalent). The nickel equivalent is an indicator of the degree of austenitization in the microstructure of stainless steel weld metal; its value is determined by converting the amounts of austenizing elements present in the weld metal such as nickel, carbon, manganese, etc., into an equivalent amount of nickel based on the intensity of their austenitizing effect ； The abscissa is represented by creq (chromium equivalent), which is an indicator of the degree of ferritization in the microstructure of the weld metal. Its value is determined by converting the amounts of the elements that contribute to ferritization in the weld structure (such as chromium, molybdenum, silicon, niobium, etc.) into an equivalent amount of chromium, based on the intensity of their ferritizing effect. The figure indicates the areas corresponding to various microstructures such as A (austenite), F (ferrite), M (martensite), etc. Based on the chemical composition of the base material to be welded and the welding filler material, the chemical composition of the weld metal is determined using the fusion welding dilution factor, which is then converted into nickel equivalent and chromium equivalent. This allows it to be determined from the microstructure diagram what phases are present in the weld metal as well as its ferrite content. Conversely, the corresponding nickel equivalent and chromium equivalent values can also be determined based on the phase composition requirements of the weld metal structure. Then, the chemical composition of the weld metal is adjusted based on this organization diagram. There are posts with Schaeffler diagrams on this forum: http://bbs.hcbbs.com/forum.php?t ... wthread&tid=1200588