Paper Title:
The Grain Boundary Embrittlement and De-Embrittlement Mechanism in Age Hardenable Fe-Ni-Ti Steels
  Abstract

The strengthening and grain boundary embrittlement in an age hardenable Fe-20.4Ni-2.8Ti ternary alloy were investigated. The Vickers hardness and tensile properties were evaluated using a Vickers hardness and tensile tester and the precipitation behavior during aging treatment was observed by transmission electron microscopy (TEM). The fracture surface was observed using low voltage field emission scanning electron microscopy (FE-SEM). The alloy showed typical aging hardening curves with a single aging peak near 640 HV, but was found to undergo severe grain boundary embrittlement from the initial stages of aging treatment. Many fine particles were observed at the grain boundary fracture surface. These particles were identified as η-Ni3Ti precipitates nucleated at the prior austenite grain boundaries. When the aging time was extended, austenite nucleated at the interface of the matrix and η-Ni3Ti precipitate. With the formation of the austenite, the tensile ductility was recovered. It was concluded that the precipitation of the η-Ni3Ti intermetallic particles at the prior austenite grain boundaries and formation of the austenite are the main causes of embrittlement and subsequent de-embrittlement in aging of this alloy.

  Info
Periodical
Solid State Phenomena (Volume 118)
Edited by
Jang Hyun Sung, Chan Gyu Lee, Yong Zoo You, Young Kook Lee and Jae Young Kim
Pages
469-474
DOI
10.4028/www.scientific.net/SSP.118.469
Citation
M. S. Kim, Y. U. Heo, H. C. Lee, "The Grain Boundary Embrittlement and De-Embrittlement Mechanism in Age Hardenable Fe-Ni-Ti Steels", Solid State Phenomena, Vol. 118, pp. 469-474, 2006
Online since
December 2006
Export
Price
$32.00
Share

In order to see related information, you need to Login.

In order to see related information, you need to Login.

Authors: J.K. Kim, Dong-Seok Chung, H.S. Park, Manabu Enoki
Abstract:The effect of beryllium (Be) on the precipitation behaviors and mechanical properties of Al–Cu–Li–Mg–Zr–(Ag) alloys was investigated. The...
381
Authors: Z. Horita
Abstract:The process of severe plastic deformation (SPD) makes it possible to reduce the grain size to the submicrometer or nanometer range in many...
1485
Authors: Wee Do Yoo, Jong Hoon Lee, Kuk Tae Youn, Young Mok Rhyim
Abstract:The microstructures and mechanical properties of 17-4 PH stainless steel at each steps of heat treatment, such as homogenizing, solid...
15
Authors: Zhong Bo Zhou, Jin Shan Li, Hong Chao Kou, Zhi Shou Zhu, Bin Tang, Hui Chang
Abstract:In order to develop a perspective of the new metastable β titanium alloy——TB-13, the influence of ageing treatments on the microstructure and...
859
Authors: Long Fei Zuo, Zhan Lei Wei, Ri Ni, Ben Ma, Zi Dong Wang
Chapter 1: Material Science and Engineering
Abstract:A kind of 1000MPa low carbon bainitic steel belonged to the Fe-Cu-Nb series was hot rolled and aged, the influence of aging temperatures on...
376