Determination of lower bound fracture toughness of a high strength low alloy steel welded joint

Abstract

The use of high-strength low-alloy steels for high performance structures (e.g. pressure vessels and pipelines) requires high strength consumables to produce an overmatched welded joint. This globally overmatched multipass welded joint contains two significantly different microstructures, as welded and reheated. In this paper, the influence of weld metal microstructure on fracture behaviour is estimated in comparison with the fracture behaviour of composite microstructures (as welded and reheated). The lower bound of fracture toughness for different microstructures was evaluated by using the modified Weibull distortion. The results, obtained using specimens with crack front through the thickness, indicated low fracture toughness, caused by strength mismatching interaction along thevcrck front. In the case of through thickness specimens, at least one local brittle microstructure is incorporatedin the process zone at the vicinity of the crck tip. Hence, unstable fracture occurred with small or without stable crack propagation. Despite the fact that the differences between the impact toughness of a weld metal and that of base metal are insignificant, the future toughness of a weld metal can be significantly lower.

Keywords

zvarni spoji;lomna mehanika;CTOD;visokotrdnostna jekla;trdnostno neujemanje;lomna žilavost;welded joints;fracture mechanics;Crack tip opening displacement;high strength seeel weld;mismatch effects;fracture toughness;resistance curves;

Data

Language:	English
Year of publishing:	2005
Typology:	1.01 - Original Scientific Article
Organization:	UM FS - Faculty of Mechanical Engineering
UDC:	621.791.05:539.4
COBISS:	9517590
ISSN:	1362-1718
Views:	1766
Downloads:	91
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	English
Secondary keywords:	zvarni spoji;lomna mehanika;CTOD;visokotrdnostna jekla;trdnostno neujemanje;lomna žilavost;
URN:	URN:SI:UM:
Pages:	str. 252-258
Volume:	ǂVol. ǂ10
Issue:	ǂno. ǂ2
Chronology:	2005
ID:	8718284