Impact Factor:2.4
DOI number:10.1007/s40195-016-0469-z
Affiliation of Author(s):中国科学院金属研究所
Teaching and Research Group:0
Journal:Acta Metallurgica Sinica-English Letters
Place of Publication:中国
Funded by:中国国家自然科学基金，中国科学院重点研究计划
Key Words:Nb; Mo; Laves phase; Microstructure; Mechanical properties
Abstract:A series of Ni–Cr–Fe welding wires with different Nb and Mo contents were designed to investigate the effect of Nb and Mo on the microstructure, mechanical properties and the ductility-dip cracking susceptibility of the weld metals by optical microscopy (OM), scanning electron microscopy, X-ray diffraction as well as the tensile and impact tests. Results showed that large Laves phases formed and distributed along the interdendritic regions with high Nb or Mo addition. The Cr-carbide (M 23C6) was suppressed to precipitate at the grain boundaries with high Nb addition. Tensile testing indicates that the ultimate strength of weld metals increases with Nb or Mo addition. However, the voids formed easily around the large Laves phases in the interdendritic area during tensile testing for the weld metal with high Mo content. It is found that the tensile fractographs of high Mo weld metals show a typical feature of interdendritic fracture. The high Nb or Mo addition, which leads to the formation of large Laves phases, exposes a great weakening effect on the impact toughness of weld metals. In addition, the ductility-dip cracking was not found by OM in the selected cross sections of weld metals with different Nb additions. High Nb addition can eliminate the ductility-dip cracking from the Ni–Cr–Fe weld metals effectively.
Note:0
Indexed by:研究论文
Discipline:Engineering
Volume:29
Issue:10
Page Number:928-939
ISSN No.:2194-1289
Translation or Not:no
Date of Publication:2016-01-01