Title:Laser beam hardening of carbon and low alloyed steels: discussion of increased quantity of retained austenite Author(s): Fedosov, S.A. Author Affiliation: Samara State Technical Univ (SSTU) Source: Journal of Materials Science v34 n17 1999 Kluwer Academic Publishers Dordrecht Netherlands p 4259-4264 0022-2461 JMTSAS Abstract: It was shown that mainly three effects are responsible for the increased quantity of retained austenite in carbon and low alloyed steels after laser transformation hardening. At low peak temperatures a high dislocation density appears in the initial austenite phase during the reversed polymorphic transformation which is preserved till the martensite transformation begins and retards this reaction. At high peak temperatures this is more complete carbides dissolution than after standard furnace hardening. Both effects are overlapped by a third one. This is the carbon up-hill diffusion resulting in surface enrichment of carbon and a decrease of the martensite start temperature. English (Author abstract) 39 Refs. Subjects: Steel Hardening; Laser beam effects; Austenite; Martensitic transformations; Dislocations (crystals); Austenitic transformations; Temperature; Dissolution; Diffusion; Cooling; Classification Codes: 545.3; 537.1; 744.8; 531.1; 531.2; 933.1.1 Document Type: JA Identifiers: Laser beam hardening; Carbon up-hill diffusion; Polymorphic transformation
Compendex 1996 DIALOG No: 04315147 EI Monthly No: EIP96012987542 Title: The analysis of causes for gamma -phase quantity increasing under laser irradiation of quenched high-carbon and low-alloyed steels Author: Fedosov, S.A. Corporate Source: Samarskij Gosudarstvennyj Tekhnicheskij Univ, Samara, Russia Source: Fizika i Khimiya Obrabotki Materialov n 3 May-June 1995. p 40-48 Publication Year: 1995 CODEN: FKOMAT Language: Russian Document Type: JA; (Journal Article) Treatment Code: A; (Applications); X; (Experimental) Abstract: It was shown that mainly three cause are responsible for that effect in U12, 45 and ShKh15 steels. At low heating temperatures this is high dislocation density appeared in initial austenite phase during the reversed polymorphic transformation which is preserved till martensitic reaction beginning and retards this reaction. At high temperatures this is more complete carbides dissolution than after conventional furnace quenching. On two both causes the effect of third mechanism overlaps. This is the appearanc of carbon upgoing diffusion resulting in steel surface enrichment with carbon and martensitic point decreasing. 32 Refs. Descriptors: *Metals; Carbon steel; Radiation effects; Laser beam effects; Phase composition; Temperature control; Crystal defects; Carbon; Diffusion; Phase transitions Identifiers: Polymorphism EI Classification Codes: 622.2 (Radiation Effects) 531 (Metallurgy & Metallography); 622 (Radioactive Materials)
Compendex 1993 DIALOG No: 03540441 EI Monthly No: EI9301000637 Title: X-ray diffraction analysis of the substructure of retained austenite after laser treatment structural steels. Author: Fedosov, S. A. Source: Physics and Chemistry of Materials Treatment (English translation of Fizika i Khimiya Obrabotki Materialov) v 26 n 1 Jan-Feb 1992 p 98-102 Publication Year: 1992 CODEN: PCMTEU ISSN: 0264-729X Language: English Document Type: JA; (Journal Article) Treatment Code: X; (Experimental) Abstract: X-ray diffraction analysis was carried out to examine the substructure of retained austenite in structural steels after furnace quenching and laser treatment under different conditions. The results show that the parameters of the substructure of retained austenite depend on its content in the steel and are clearly independent of the type of heat treatment (furnace or laser) and chemical composition of the steel, and depend on them only through the effect of the latter on the amount of the retained austenite. (Author abstract) 10 Refs. Descriptors: *AUSTENITE; STEEL; HEAT TREATMENT; X RAY ANALYSIS; MICROSTRUCTURE; LASER APPLICATIONS Identifiers: SUBSTRUCTURE; LASER TREATMENT; STRUCTURAL STEEL EI Classification Codes: 545 (Iron & Steel); 744 (Lasers); 537 (Heat Treatment); 801 (Chemical Analysis & Physical Chemistry) DIALOG No: 03630535 EI Monthly No: EIP93050802249 Title: Quasistationary roughness in case of pulse laser treatment of steels. Author: Fedosov, S.A. Corporate Source: Politekhnicheskij Inst, Samara, Russia Source: Trenie i Iznos v 13 n 2 Feb 1992. p 356-362 Publication Year: 1992 CODEN: TRIZD6 ISSN: 0202-4977 Language: Russian Document Type: JA; (Journal Article) Treatment Code: A; (Applications); T; (Theoretical); X; (Experimental) Abstract: Change of roughness in surfaces of ShKh15 (1.0%C-1.5%Cr-Fe), 12Kh1 (1.2%C-1%Cr), R18 (0.8%C-18%W-4.%Cr-1%V-Fe) steels under the effect of pulsed laser treatment was studied. Quasistationary roughness to which roughness of samples following several pulses was approaching was observed in case of pulsed laser treatment. Surface roughness could be reduced to Ra equals 0.2 mkm by pulsed laser treatment. Treatment regime of 3 pulses per each spot was shown to be optimum from this point of view. Possible mechanisms resulting in formation of quasistationary roughness and thus leading to stationary one were discussed. 8 Refs. Descriptors: *Friction; Roughness measurement; Surfaces; Steel; Laser beam effects; Surface properties; Laser pulses; Wear of materials; Surface testing Identifiers: Quasistationary roughness EI Classification Codes: 931.2 (Physical Properties of Gases, Liquids & Solids); 901.3 (Engineering Research); 744.9 (Laser Applications) 931 (Applied Physics); 901 (Engineering Profession); 744 (Lasers) Title: DETERMINATION OF THE QUALITY OF A WELD SPOT BY ITS VISUAL APPEARANCE DURING LASER SPOT WELDING WITH DEEP PENETRATION Author: Fedosov, S.A.; Author Affiliation: Source: Svarochnoe Proizvodstvo n 6 Jun 1992 p 16 ISSN: 0491-6441 CODEN: SVAPAI No Abstract
Compendex 1992 DIALOG No: 03482956 EI Monthly No: EI9209119969 Title: Stability of residual austenite after laser treatment of steels. Author: Fedosov, S. A. Source: Fizika i Khimiya Obrabotki Materialov n 3 May-Jun 1991 p 141-142 Publication Year: 1991 CODEN: 500047 Language: Russian Document Type: JA; (Journal Article) Treatment Code: X; (Experimental); A; (Applications) Abstract: Large amount of residual austenite is fixed in carbon steels after laser treatment. Temperature stability of residual austenite after pulsed laser irradiation of carbon steel and ShKh15 type steel was studied. It is shown that after laser treatment residual austenite is characterized by the same temperature stability like after usual quenching. Temperature stability of residual austenite in both steels does not depend on carbon content and the initial level of residual austenite. Data on residual austenite decomposition in ShKh15 steel after laser treatment and 3 year holding at room temperature show its level reduction from 40-42 to 35-37 %. 1 Ref. In Russian. Descriptors: *STEEL HEAT TREATMENT--*Laser Applications; IRON AND STEEL METALLOGRAPHY--Austenite; CARBON--Concentration; THERMAL EFFECTS--Stability; CARBON STEEL Identifiers: RESIDUAL AUSTENITE STABILITY EI Classification Codes: 537 (Heat Treatment); 545 (Iron & Steel); 531 (Metallurgy & Metallography); 804 (Chemical Products) DIALOG No: 03069945 EI Monthly No: EI9106074060 Title: Effect of laser treatment on the retained austenite content of carbon and chromium steels. Author: Fedosov, S. A. Source: Physics and Chemistry of Materials Treatment (English translation of Fizika i Khimiya Obrabotki Materialov) v 24 n 5 Sep-Oct 1990 p 441-444 Publication Year: 1990 CODEN: PCMTEU ISSN: 0264-729X Language: English Document Type: JA; (Journal Article) Treatment Code: X; (Experimental) Abstract: Investigations were carried out into the effect of the concentration of carbon and chromium and the laser treatment conditions and th amount of retained austenite in steels. Laser treatment was carried out using pulsed time in the millisecond range in three conditions: with melting without, melting and with heating to the temperatures in the single-phase region (complete quenching), and with heating to the temperatures of the two-phase range (partial quenching). (Author abstract) Descriptors: *STEEL HEAT TREATMENT--*Laser Applications; CARBON STEEL--Heat Treatment; IRON AND STEEL METALLOGRAPHY--Austenite Identifiers: LASER TREATMENT EFFECT; RETAINED AUSTENITE CONTENT; CHROMIUM STEELS EI Classification Codes: 545 (Iron & Steel); 744 (Lasers); 537 (Heat Treatment)
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