The Structure and Toughness of the Weld Heat-Affected zone of A C-Mn-V Steel
Abstract:
THE COARSE AND FINE GRAINED REGIONS of the weld heat affected zone (HAZ) of a V-bearing microalloy ship-plate steel were simulated using the Gleeble 1500, a weld-thermal simulator. Charpy blanks were thermally cycled to temperatures of l350°C and l000°C and cooling times from 800°C to 500°C of 42s and 200s were used to represent heat inputs of 4 kJ/mm and 8 kJ/mm respectively on 25 mm plate. The notch toughness of these simulated materials were evaluated from V-notch Charpy tests conducted over a range of temperatures.
The simulated coarse grained HAZ (peak temperature (Tp) l350°C) was found to have the same notch toughness for both heat inputs. The toughness in each case was found to be dependent on the prior austenite grain/bainite packet size and independent of the volume fraction of proeutectoid ferrite and the bainitic ferrite grain width.
The simulated fine grained HAZ (peak temp. l000°C) had lower toughness in the case of the lower heat input. The reason for the lower toughness was the presence of a significant volume fraction of coarse bainite as compared to the low volume fraction of pearlite present in the higher heat input samples.
Keywords:
vanadiun, weld HAZ.
Author:
J. T. Bowker (1), A. G. Glover (2) and R. B. Lazor (2)
Affiiation
(1) PMRL, CANMET, Energy Mines and Resources, Ottawa, Canada
(2) Welding Institute of Canada, Oakville, Ontario, Canada
PDF:
Source:
Vanadium Structural Steels - Reprint of papers on vanadium steel from the proceedings of “ASM HSLA Steels Technology and Applications Conference, Philadelphia, USA, Oct., 1983, pp.257-266
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