On the issue of uneven impact energy in the heat-affected zone after welding of 09MnNiDR
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This post was last edited by 15837357920 on 2016-11-5 at 14:59. There is a device available, made of material 09MnNiDR with a thickness of 54 mm; after welding, the impact energy in the weld area at -50 degrees is above 200 J. Heat-affected zone: Impact energy at -50 degrees – two values above 200 J, and one value of 10 J. Several of them are, it’s not a coincidence. The raw materials have passed retesting; the impact strength at -70 degrees is above 200 J for all three tests. Have any of you sea friends encountered this? What caused it? How to analyze it. Is it a material issue or a welding issue?
Either the material is defective or there was an operational error.
What kind of operation do you mean? Testing or welding?
It’s a bit inappropriate to simply conclude it as a welding issue. 1. There are no issues in the weld area; the impact value is very high, and the heat input is low. 2. It’s not an isolated case; there was a problem once, and even after taking precautions, it happened again. 3. There are highs and lows every time.
I think there was an error during the experimental operation.
Repeat the experiment; this situation occurs as well.
Since the problem keeps recurring, it must be a welding issue. From which part of the heat-affected zone do the specimens with excessively low impact values come from (the root of the groove, the surface, or randomly)? If they all come from the same area, it’s easier to find the cause. Are there any differences in the hardness and microstructure of this area? If the grains there are particularly large, it can also help identify the cause. Should the welding parameters also vary depending on the groove width at various weld passes along the thickness, as well as the preheating and cooling conditions? There is a certain degree of variability in the impact values of welds and heat-affected zones; a difference of several dozen J is considered normal, but a difference of 200 J and 10 J is definitely abnormal.
No matter how it’s welded, I don’t think the impact value of the heat-affected zone can be that low.
Generally, points at 1/2 and 1/4 of the thickness are taken.
If all values are low, that’s possible; but it’s abnormal when the difference is always so large.