Effect of tempering on microstructure and mechanical properties of laser welded and post-weld treated AHSS specimens
Number of Authors: 5
2017 (English)In: Materials Science Forum, ISSN 0255-5476, E-ISSN 1662-9752, Vol. 891, 18-24 p.Article in journal (Refereed) In press
An advanced high strength steel (0.08 wt.%C, 1.79 wt%Mn, 0.23 wt%Si) was subjected to different post-weld heat treatments by quenching & tempering treatments (Q&T) after laser welding to reduce the risk of martensite formation in a few seconds based on an idea of quench and partitioning (Q&P), mechanism. The thermal stability of retained austenite, microstructure development and mechanical properties have been studied at 2 tempering temperatures of 440°C (Ms) and 636°C (Bs), both for 15 minutes, by means of electron microscopy, dilatometry, hardness profile and tensile tests. Dilatometer study unveiled that redistribution of carbon atoms and precipitation of transition carbides occur around 150°C and austenite decomposition occur at 600°C. Tempering at 636°C resulted in notable effect on the mechanical properties, while no significant difference was detected at 440°C, except a slight hardness drop. The strength increased up to 12% for the different specimens without significant loss in ductility for all specimens tempered at 636°C, which may be caused by precipitation hardening and recrystallization of martensite lath boundaries during tempering around 600°C.
Place, publisher, year, edition, pages
2017. Vol. 891, 18-24 p.
laser welding, quench and temper (Q&T), dilatometer, hardness profile, tensile test
Metallurgy and Metallic Materials
Research subject Engineering Materials
IdentifiersURN: urn:nbn:se:ltu:diva-62255OAI: oai:DiVA.org:ltu-62255DiVA: diva2:1078107
16th International Symposium on Metallography and Materials Science, Stará Lesná, High Tatra Mountains, Slovak Republic, April 20-22, 2016
Konferensartikel i tidskrift 2017-03-15 (andbra)2017-03-022017-03-022017-03-15