The coexistence of acicular ferrite and bainite in an alloy-steel weld metal

Autor: Jung-Je Yang, Chih-Chung Yang, Chang-Jen Huang
Rok vydání: 1992
Předmět:
Zdroj: Journal of Materials Science Letters. 11:1547-1548
ISSN: 1573-4811
0261-8028
DOI: 10.1007/bf00729286
Popis: For a multirun weld metal the fusion zone can be classified into two main components: the primary zone obtained during cooling of the weld from the liquidus and the secondary microstructure (commonly called the reheated zone) obtained during the deposition of further weld metal. The primary zone usually consists of large columnar austenite grains at high temperatures. On the other hand, the reheated zone of a multirun weld is nominally divided into austenite coarse-grained and fine-grained regions, depending on the peak temperature to which they are exposed. The effect of the grain size of prior austenite on the acicular ferrite transformation is significant. It has been shown [1] that if the primary microstructure of the weld deposit consists essentially of acicular ferrite, then the acicular ferrite can again be obtained in the reheated homogenized weld metal when the austenite grain size is relatively large. However , classical sheaf-like bainitic ferrite can form as the austenite grain size is small. Although Babu and Bhadeshia [2] reported that the acicular ferrite and bainite can coexist (Fig. 1), there
Databáze: OpenAIRE
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