Embrittlement of Steel in Contact with Molten Copper-Zinc-Tin Alloys and Molten Sulphide

Embrittlement of steel in contact with liquid phase-II

Abstract

Mild steels in contact with molten copper-tin alloys embrittled severely in the range of 0-80%Sn, but did not embrittle in the range of 90-100% Sn.As the tin percentage in the alloys was increased and the melting point of the alloys was lowered, the embrittling temperature range was extended down to lower temperature.
Mild steel was not embrittled by pure tin, but embrittled by pure zinc and more easily by tin-zinc alloy. Mild steel in contact with the alloys containing 50% zinc and 50% tin respectively was embrittled at a temperature higher than 500°C.The cracks ran along to ferrite-grain boundaries at below A1 point.Mild steel was embrittled severly by molten copper-zinc alloy that is a brazing solder, but was not embrittled by a tin-lead solder.Some steels in contact with molten iron sulphide were embrittled.