Weld cracking and solidification behavior of titanium alloys

Journal Article · Sun Jan 01 04:00:00 EST 1995 · Welding Journal (Miami); (United States)

OSTI ID:6611985

Inoue, H; Ogawa, T ^[1]

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1. Nippon Steel Corp., Chiba (Japan). Steel Research Lab.

The weld solidification cracking behavior of three different Ti-Alloys was investigated using the Varestraint test. Ti-6Al-4V weld metal did not crack up to 8.3% augmented strain, while cracking was significant over 0.5% augmented strain in Ti-6Al-6V-2Sn and Ti-15V-3Al-3Cr-3Sn weld metal. Marked microsegregation of V, Fe, Cr and/or Cu to dendrite boundaries of each solidification microstructure was confirmed by the tin-quenching method. According to their measurements, the diffusion rate of the solute elements in Ti-6Al-4V alloy was one order of magnitude larger than that in the other two alloys. Hence, any microsegregation occurring in Ti-6Al-4V alloy was one order of magnitude larger than that in the other two alloys. Hence, any microsegregation occurring in Ti-6Al-4V weld metal during solidification was not significant due to the large solute back-diffusion in the sold, and the dispersed at an early stage of cooling after solidification. On the other hand, any microsegregation that occurred in the other two alloy welds during solidification was very noticeable due to the much smaller back-diffusion of solute elements in the sold, and the fact that it largely remained in ambient temperature owing to the slower solute diffusivity. Solute diffusion rates were determined by experiment using special diffusion couples. As a consequence of microsegregation, the solidification temperature range of Ti-6Al-6V-2Sn and Ti-15V-3Al-3Cr-3Sn alloys would be great, thus forming a residual low-melting liquid film, that resulted in cracks.

• OSTI ID: 6611985
• Journal Information: Welding Journal (Miami); (United States), Journal Name: Welding Journal (Miami); (United States) Vol. 74:1; ISSN 0043-2296; ISSN WEJUA3
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360102* -- Metals & Alloys-- Structure & Phase Studies
360103 -- Metals & Alloys-- Mechanical Properties
ALLOYS
ALUMINIUM ALLOYS
CHROMIUM
CHROMIUM ALLOYS
COPPER
CRACK PROPAGATION
DATA
ELEMENTS
EXPERIMENTAL DATA
INFORMATION
IRON
JOINTS
METALS
NUMERICAL DATA
PHASE TRANSFORMATIONS
SOLIDIFICATION
TIN ALLOYS
TITANIUM ALLOYS
TITANIUM BASE ALLOYS
TRANSITION ELEMENTS
VANADIUM
VANADIUM ALLOYS
WELDED JOINTS