TITLE:
Residual Stresses and Micro-Hardness Testing in Evaluating the Heat Affected Zone’s Width of Ferritic Ductile Iron Arc Welds
AUTHORS:
Georgios K. Triantafyllidis, Dimitrios I. Zagliveris, Dionysios L. Kolioulis, Christos S. Tsiompanis, Titos N. Pasparakis, Athanasios P. Gredis, Melina L. Sfantou, Ioannis E. Giouvanakis
KEYWORDS:
Welds, Heat Affected Zone, Residual Stresses, Micro-Hardness Vickers, Heat Affected Zone’s Width
JOURNAL NAME:
Materials Sciences and Applications,
Vol.7 No.1,
January
29,
2016
ABSTRACT: Shielded Metal Arc Welding (SMAW) in Ductile Irons (DI) is often required by foundries for practical manufacturing reasons. The mechanical properties of the welded structures are strongly dependent on their HAZ’s width. A model based on the behaviour of the ferritic matrix of high-Si DIs in order to make an approach in measuring their HAZ’s width is developed in this study. A series of thermal treatments on 3.35 and 3.75 wt% Si as-cast DIs and spot SMAWs is applied on these materials. The applied SMAWs are done on non-preheated and preheated samples (150℃ - 300℃). For welding we modify the amperage (100 - 140A). The micro-hardness Vickers changes in the ferrite of the as-cast samples and inside the HAZ of the welded ones can be attributed to the existence of residual stresses (RS) in the ferritic matrix and assist in estimating the HAZ’s width.