Grain Orientation Issue w/Normalized 4140.
Grain Orientation Issue w/Normalized 4140.
(OP)
I need to progress rapidly through a new weld procedure PQR and the only material we could get overnight was a section of AISI 4140 normalized 9-inch diameter x 12-inch long round bar. From this it was sliced into six each 6”x12” test plates. However this leaves the grain orientation parallel to the 12-inch length where it should be transverse to it (the bevel will be along the 12-inch side), which will mean that bend testing and tensile testing will place elongations across the grain rather than with the grain and this may affect test results.
The mill cert says the material was “cold str., Normalized at 900 deg C”. Does the normalizing reconfigure the grain structure of rolled bar material to where I should not need to be concerned with grain orientation affecting tensile and bend tests? Additionally, the plates will be heat treated to HRC 30-32 prior to welding.
Thanks for all advice
The mill cert says the material was “cold str., Normalized at 900 deg C”. Does the normalizing reconfigure the grain structure of rolled bar material to where I should not need to be concerned with grain orientation affecting tensile and bend tests? Additionally, the plates will be heat treated to HRC 30-32 prior to welding.
Thanks for all advice





RE: Grain Orientation Issue w/Normalized 4140.
RE: Grain Orientation Issue w/Normalized 4140.
RE: Grain Orientation Issue w/Normalized 4140.
TVP-
I do not have inclusion information, is this a test normally done by the mill? Also, the sulfur is less than .01% - why do you mention sulfur as a possible concern on this question? Why or how could higher values of sulfur affect bend or tension tests?
RE: Grain Orientation Issue w/Normalized 4140.
Sulfur produces inclusions like MnS stringers. They reduce elongation, especially in the transverse direction.
Regards,
Cory
Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips Fora.
RE: Grain Orientation Issue w/Normalized 4140.
I will be doing this procedure as a double bevel plate test, plates will be Q&T prior to weld. We will be using ER80S-Ni1 root and 1st pass with 120S-1 fill. Mechanical tests will be done in as-welded condition (no stress relief). Tension, bend and Charpy tests are required. With this in mind, are there any cautions or concerns that I need to worry about?
Thanks again to all.
RE: Grain Orientation Issue w/Normalized 4140.
The only concern with Q&T is to watch your heat input. The rest looks ok to me.
RE: Grain Orientation Issue w/Normalized 4140.
I often search for heat input reference data or limits in terms of kJ/inch but this is rare information to find on 41xx steels and other mild steels. Reference values for the "T8/5" you once told me about is also non-existent for 41xx in the public domain. Any suggestions on that?
Lacking a kJ/inch or a T8/5 value to help me back into ideal amp and travel speed, I will use the following as a start:
400 deg F preheat;
500 max interpass;
180 amps on fill pass; probably less on root & first pass;
~24 volts;
weld speed ~8 in/min;
finish off with the ubiquitous "wrap & slow cool".
RE: Grain Orientation Issue w/Normalized 4140.
The interpass temperature at 500 deg F is a good choice to avoid changing bulk properties.
RE: Grain Orientation Issue w/Normalized 4140.
Take a look at the link below, it might be of interest to you. Also, credit for this link is from my newsletter subscription with
welding-advisers.com
htt
RE: Grain Orientation Issue w/Normalized 4140.
Say, if you look at my procedure outline above, I am using 80S-Ni1 for the root and 1st pass; will this impair or prevent any post production RT examination that will be required??
RE: Grain Orientation Issue w/Normalized 4140.
No.