The Role of Trapping on Hydrogen Transport and Embrittlement.
Abstract
The achieved goal of the present research was to propose sets of criteria that would help in the design of alloys more resistant to hydrogen embrittlement. The research is based upon the original idea that a fine and homogeneous distribution of particular kinds of traps could achieve the above goal. This starting idea was developed from an investigation of existing hydrogen embrittlement theories, which showed that a common factor of all theories was the presence in the matrix of large deleterious accumulations of hydrogen at specific sites. Fe-Ti alloys in both the carburized and uncarburized condition were chosen as the model material to simulate internal trapping of hydrogen. Microstructure characterization revealed that all alloys consisted of a ferrite matrix in which free substitutional titanium atoms and titanium carbide particles were present. Techniques were developed to distinguish between reversible traps (titanium atoms, dislocations, grain boundaries, coherent particles) and irreversible traps (such as titanium carbide particles). This characterization separation was achieved both experimentally (using an electrochemical permeation cell) and theoretically (by proposing two new models of reversible and irreversible trapping, and by comparison with existing theories). (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1977
- Accession Number
- ADA045331
Entities
People
- Gerard M. Pressouyre
- I. M. Bernstein
Organizations
- Carnegie Mellon University