کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
798286 903234 2012 14 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Feasibility of laser surface treatment of pearlitic and bainitic ductile irons for hot rolls
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مهندسی صنعتی و تولید
پیش نمایش صفحه اول مقاله
Feasibility of laser surface treatment of pearlitic and bainitic ductile irons for hot rolls
چکیده انگلیسی

The effects of laser surface treatment on the microstructure, crackability and stresses generated on laser hardened layers produced in several ductile cast iron materials were investigated. Two kinds of alloys having pearlitic (SGP) and acicular (SGA) matrix microstructures were selected. Hardened layers with thicknesses ranging from 1.5 to 2.5 mm were obtained by means of laser remelting (LSRm) or laser hardening (LSH). Thermal stresses generated upon laser processing have been estimated by a simple thermal model. For energy densities delivered onto the material at above 40 J/mm2, extensive cracking was developed in SGA and SGP irons due to the contribution of thermal stresses. By lowering the energy density, crack formation was avoided in SGP irons only. At low energy densities, crack formation is controlled by the generation of transformational stresses due to excessive austenite retention. An increase of the surface temperature or the alloying content gave rise to an increase of the retained austenite and the formation of lower bainite at the remelted zone and the heat affected zones, respectively. KC fracture toughness of Fe3C carbides embedded in pearlitic and acicular matrixes was measured by means of the nano-indentation technique. Fracture toughness of cementite in SGP irons was slightly higher than in SGA irons, which can help to reduce the crackability of LSH layers.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Materials Processing Technology - Volume 212, Issue 5, May 2012, Pages 989–1002
نویسندگان
, , ,