Open AccessEffects of interactive particles on steel weldability
Author(s) -
Casper van der Eijk,
Øystein Grong,
S. S. Babu,
S. A. David
Publication year - 1998
Language(s) - English
Resource type - Reports
DOI - 10.2172/290923
Subject(s) - charpy impact test , materials science , metallurgy , weldability , nucleation , welding , ferrite (magnet) , toughness , microstructure , acicular ferrite , composite material , austenite , bainite , thermodynamics , physics
The concept of intragranular ferrite nucleation by specific inclusions is well known from steel weld metals. In this paper it is shown that the idea can be transferred to steel metallurgy. Control of the inclusion composition and thus the nucleation potency with respect to ferrite can readily be achieved by the choice of an appropriate deoxidation procedure. Thermodynamic (Thermo-Calc) calculations in addition to X-ray mappings and microprobe analysis are employed to understand and predict the inclusion formation in the steels. Three different steels, two of them Ti-deoxidized, and one Al-Ca-deoxidized, have been subjected to weld thermal simulation at different peak temperatures and cooling programs followed by Charpy-V notch testing at {minus}40 C to reveal differences in the HAZ toughness. The results from these tests show that the titanium deoxidized steels exhibit excellent toughness in the grain coarsened HAZ after high heat input weld simulation because of a refinement of the microstructure. This observation is in contrast to the more traditional behavior of the conventional Al-Ca deoxidized steels, which show no evidence of intragranular ferrite formation