Transient liquid phase bonding of carbon steel components using Ni-based foils – A comprehensive joint characterization

DI LUOZZO, NICOLÁS; DI LUOZZO, NICOLÁS; BOUDARD, MICHEL; BOUDARD, MICHEL; FONTANA, MARCELO; FONTANA, MARCELO

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

ELSEVIER SCIENCE SA

Año: 2019 vol. 751 p. 51 - 61

0921-5093

The transient liquid phase bonding (TLPB) process is one of the selected joining technologies to replace threaded connections in solid expandable tubulars. In particular, for expandable hot-rolled seamless carbon steel tubular products using Ni-based amorphous metallic foils as filler material. In this work, a comprehensive mechanical properties and microstructural characterization was carried out in TLP-bonded bars for this base metal/filler material combination. Both the joint and the heat affected zone exhibited a strength which compares well with the base metal, and a ductility in accordance with that which is typically specified for steel arc-welded joints. A coalesced lath-like bainitic microstructure was found at the joint. In addition, and by means of orientation imaging, a parent austenite grain - which is shared by the joint and an adjacent ferrite grain from the base metal - was found, which demonstrates the epitaxial nature of the TLPB solidification process. Also, a cell-block-like structure at ferrite grains next to the joint was detected, due to the plastic deformation developed in tensile-tested samples at room temperature.