Laser-glazing low carbon iron fracture samples

• Published in: Journal of materials science 1985-06, Vol.20 (6), p.1929-1933
• Main Author: RAWERS, J. C
• Format: Article
• Language: English
• Subjects: Applied sciences; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Fractures; Materials science; Mechanical and acoustical properties of condensed matter; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals, semimetals and alloys; Metals. Metallurgy; Physics; Specific materials
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/bf01112274

Charpy samples of carbon steel (1018, 1040) were laser-glazed in the V-notch root, resulting in highly modified fracture properties and radially altered crystal structure. Laser-glazing produced two distinct regions: an inner region, next to the bulk material, which was heated above the austenitic transition temp., was cooled rapidly, and produced a retained austenitic phase; and an outer region, next to the V-notch surface, which was heated above the melting temp., cooled more slowly, although still very rapidly, and transformed predominantly into the martensite phase. Instrumented impact testing of laser-glazed samples produced fracture energies and fracture toughness values similar to samples prepared by currently accepted ASTM precracking procedures. Laser-glazing is offered as an alternative to existing procedures as an experimental technique for testing fracture toughness samples and, especially, for testing substandard size samples and hard-to-prepare, fracture toughness materials samples. 22 ref.--AA