HWooldridge Posted October 3, 2009 Share Posted October 3, 2009 This post is primarily aimed at the newer smiths among us; although it looks burned, this material was not overheated (at least - not by me). I started with a virgin 3/16"x1/2" hot-rolled bar and was in the process of making a dozen scroll tips to weld onto some branching elements. One scroll cracked like these pictures, so I cut back the bar twice more with repeat performances every time. I finally got about 2 feet back from the original bar end and the cracking problem went away. The rest of the bar seemed fine and no other cracks were evident. Just goes to show that you may experience troubles which are not of your doing... Quote Link to comment Share on other sites More sharing options...
meinhoutexas Posted October 3, 2009 Share Posted October 3, 2009 could his have been over heated at the mill and they just missed it? Quote Link to comment Share on other sites More sharing options...
HWooldridge Posted October 3, 2009 Author Share Posted October 3, 2009 Sure, that's possible. It does look overheated. Quote Link to comment Share on other sites More sharing options...
BIGGUNDOCTOR Posted October 3, 2009 Share Posted October 3, 2009 At the screwmachine shop I work at we have had bar stock that came in with internal cracking, voids, etc.The cracking on your bar may have been caused by improper rolling at the mill-too cold / work hardening? Quote Link to comment Share on other sites More sharing options...
thecelticforge Posted October 3, 2009 Share Posted October 3, 2009 I am thinking a bit of slag. Quote Link to comment Share on other sites More sharing options...
Nakedanvil - Grant Sarver Posted October 3, 2009 Share Posted October 3, 2009 (edited) Interesting, but it's only the part that's been forged that cracked. The un-forged part that is bent shows no cracking. Explain that. Edited October 3, 2009 by nakedanvil Quote Link to comment Share on other sites More sharing options...
HWooldridge Posted October 3, 2009 Author Share Posted October 3, 2009 Interesting, but it's only the part that's been forged that cracked. The un-forged part that is bent shows no cracking. Explain that. True - and it did not appear cracked before forging. I forged every scroll in my gas forge at a bright yellow heat and the end of that one bar was the only piece produced parts like this. None of the other scrolls had the slightest appearance of cracking - and - the scroll made behind the cutoff looked fine also. The condition appeared only within about a two foot section and only when bent. Quote Link to comment Share on other sites More sharing options...
Nakedanvil - Grant Sarver Posted October 3, 2009 Share Posted October 3, 2009 I have to admit I've used and abused a lot of steel and it would be pretty hard to say it was anything YOU did wrong. Yeah, had to be some junk steel. Quote Link to comment Share on other sites More sharing options...
HWooldridge Posted October 4, 2009 Author Share Posted October 4, 2009 I have to admit I've used and abused a lot of steel and it would be pretty hard to say it was anything YOU did wrong. Yeah, had to be some junk steel. The hot rolled stuff I get locally is often pretty lousy with regard to cold shuts and seams. I've had several instances where I pulled a strip out of a piece that looked like flash or some other type of debris was rolled into the bar. The spec for A36 is relatively wide but one would think the mills could run the stuff with a little more care - of course, most is produced off-shore and imported so maybe I shouldn't be surprised. Quote Link to comment Share on other sites More sharing options...
Ted T Posted October 4, 2009 Share Posted October 4, 2009 Thank you for sharing information about this rare episode while you were forging. In over a half century of forging I have only had a couple of occasions where mild steel acted similar to the way yours did. But I remember them very well because it made me question my forging skills! Each time it occurred I just blamed it on my self. But as I moved on, it always left me with a question of about Quote Link to comment Share on other sites More sharing options...
CurlyGeorge Posted October 4, 2009 Share Posted October 4, 2009 Hey Ted. I know Dr Phil. We go to the same barber.LOL :D Quote Link to comment Share on other sites More sharing options...
HWooldridge Posted October 4, 2009 Author Share Posted October 4, 2009 More observations: I went out to the shop tonight and played around with this piece of material. I found it only exhibits this characteristic while bending hot. It does not crack visibly when bent cold to a 90 (I didn't look under magnification but looks clean to my bare eye). It does not come to pieces while forging - but does crack when bent anywhere from a dark red to a bright yellow. In fact, it seems to get a little worse at higher temps. I have read this is usually termed "hot-short" and can be due to excessive sulfur. What do y'all think? Quote Link to comment Share on other sites More sharing options...
Francis Trez Cole Posted October 4, 2009 Share Posted October 4, 2009 I have seen that effect with tool steel being worked to cold Quote Link to comment Share on other sites More sharing options...
anvillain Posted October 4, 2009 Share Posted October 4, 2009 I think you are right on! HOT SHORTS often smell like sulphur also! :-) Anvillain Quote Link to comment Share on other sites More sharing options...
Ten Hammers Posted October 4, 2009 Share Posted October 4, 2009 (edited) I have forged a fair amount of 14-16 ga sheet. This is production stuff for a customer I have. For the large part in coal/charcoal although gas forge used in the last 4-5 years as well. Sometimes I get a spot in the sheet that just melts away. Looks like a piece of butter was dropped onto the sheet just before it melts away. I blame it on a beer can or perhaps a piece of aluminium heater core from a car that made it into the melt although I am a rookie in comparison to some of you folks. Yes I have also had a piece or 2 of strange acting bar or round. Normally very hard spots and I just blame that on a bearing in the melt (although I have slept more than once since this occurance). I will say this: Old re-claimed steel has never acted in this fashion (silo banding, old ag ateel of other fashion etc). It has always been new steel. Ted, I thought that fellas new name was Dr Philo ? Edited October 4, 2009 by Ten Hammers Quote Link to comment Share on other sites More sharing options...
Don A Posted October 6, 2009 Share Posted October 6, 2009 I was guessing sulfer as soon as I saw your first post. I know they intentionally introduce sulfer into some steels to improve the machinability. Perhaps this batch had a high dose of that in the remelt. Just a guess, though. We'll have to ask the Chinese to know for sure. Probably a piece of remelted "clunker" from our latest stimulus program. Quote Link to comment Share on other sites More sharing options...
dimenickel Posted October 6, 2009 Share Posted October 6, 2009 maybe steadite... goes liquidy around 970 cel Quote Link to comment Share on other sites More sharing options...
Kendrick Posted October 6, 2009 Share Posted October 6, 2009 That looks EXACTLY like the cracking I was having trouble with on the tent stakes I was complaining about a couple of months ago. The entire section I was using on that project did that although I haven't had any trouble with any projects since then. (not using the same stock either) Quote Link to comment Share on other sites More sharing options...
pkrankow Posted October 6, 2009 Share Posted October 6, 2009 steadite: Definition from Answers.com not very hot at all, relatively speaking. Its a orange or yellow heat. Phil Quote Link to comment Share on other sites More sharing options...
patrick Posted October 7, 2009 Share Posted October 7, 2009 Sulfur certainly will make steel hot short as will and excess of copper or lead. Sulfer and lead are both sometimes added to improve machinability, though lead is not as widely used any more for environmental reasons. Steel with several % of surlfer, such as 1117 or 1144 is still quite forgable though. I had a somewhat similar condition occur recently when forging H13. In my case, I had previoiusly overheated and melted some copper in the forge. The H13 was sitting in the pool of liquid copper and I think that some of that copper wicked up along grainboundries on the surface of the H13. This weakend the grain boundaries and allowed tearing to occur. As far has having a chunck of Aluminum or a bearing in a bar and that causing problems-this is very, very unlikely due to the way steel is produced. Aluminum has such a low melting point that if it were in the scrap metal, it would melt and be absorbed into the liquid steel like any other element. The same thing would happend to a bearing. Even if the bearing didn't melt, the original heat treatment would be completely undone. This is not to say you can't have hard spots in steel, because you certainly can. But they are much more likely to be the result of non-uniform cooling at the mill than to imcoplete melting and homoginization of the the raw materials. Patrick Quote Link to comment Share on other sites More sharing options...
Sam Thompson Posted October 7, 2009 Share Posted October 7, 2009 I remember being told as a kid that the best way to wind up a smith was to chuck a copper penny into the fire but I've never tried it... Is that what happens? Quote Link to comment Share on other sites More sharing options...
Walking Dog Posted October 7, 2009 Share Posted October 7, 2009 I have had exactly the same experience with a piece of 1/2 square reclaimed from a section of fencing of unknown provenance, but it looks like newer rather than older stuff. I got the same cracking when bending it hot. I also questioned my forging abilities, and tried again at a higher heat, with equally bad results. This happened at a demo, so I had to change the theme of my project on the fly. When I got home to the rest of my stock, there was no problem - just this piece. Quote Link to comment Share on other sites More sharing options...
ThomasPowers Posted October 7, 2009 Share Posted October 7, 2009 Copper was supposed to block forge welding. Quote Link to comment Share on other sites More sharing options...
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