Open this publication in new window or tab >>2018 (English)In: Metals, ISSN 2075-4701, Vol. 8, no 10, article id 747Article in journal (Refereed) Published
Abstract [en]
To improve the weld zone properties of Advanced High Strength Steel (AHSS), quenching and partitioning (Q&P) has been used immediately after laser welding of a low-carbon steel. However, the mechanical properties can be affected for several reasons: (i) The carbon content and amount of retained austenite, bainite, and fresh martensite; (ii) Precipitate size and distribution; (iii) Grain size. In this work, carbon movements during the partitioning stage and prediction of Ti (C, N), and MoC precipitation at different partitioning temperatures have been simulated by using Thermocalc, Dictra, and TC-PRISMA. Verification and comparison of the experimental results were performed by optical microscopy, X-ray diffraction (XRD), Scanning Electron Microscop (SEM), and Scanning Transmission Electron Microscopy (STEM), and Energy Dispersive Spectroscopy (EDS) and Electron Backscatter Scanning Diffraction (EBSD) analysis were used to investigate the effect of martensitic/bainitic packet size. Results show that the increase in the number density of small precipitates in the sample partitioned at 640 °C compensates for the increase in crystallographic packets size. The strength and ductility values are kept at a high level, but the impact toughness will decrease considerably.
Place, publisher, year, edition, pages
MDPI, 2018
Keywords
low-carbon AHSS, Q&P, toughness, modelling, precipitation, martensite packet
National Category
Metallurgy and Metallic Materials Other Materials Engineering
Research subject
Engineering Materials
Identifiers
urn:nbn:se:ltu:diva-71070 (URN)10.3390/met8100747 (DOI)000448658700011 ()2-s2.0-85053830157 (Scopus ID)
Note
Validerad;2018;Nivå 2;2018-10-05 (svasva)
2018-10-022018-10-022021-06-09Bibliographically approved