Newbie problem with O-1 steel

[ytuyuty]

Up until today I have been hammering on leaf springs, coils springs, etc. Today I started playing with known metals (wrought iron and O-1 steel). They both cracked on me during hammering.

 

1. I took a wrought iron rod, flattened it into a flat strip about 3/16" thick, and tried to bend it around a 2-inch diameter pipe with some gentle taps. It cracked. What did I do wrong? Did the iron cool too quickly while in contact with the pipe?

2. I bought some O-1 steel (3/8" x 1" rectangular bar). It cracked just hammering to thin it (see photo). The piece in the photo is still 1/4" thick. Was I working it too hot or too cold?

[Steve Sells]

depends on what temperature it was,  many alloy steels have narrow ranges to work it, and  wrought needs  nearly white white for some grades, there is a bit of talk about both issues in knife section. also about air cooling O1

[Latticino]

When I have worked with wrought I've been cautioned that it can be quite variable depending on manufacture. We consolidated ours to help with inclusions before attempting any significant forging. The consolidation and all forging were done at almost welding temperatures, but at that heat it moved like butter. 

Don't know what you're problems are with the O1.  I actually did some forging of an integral or two from some 3/4" O1 recently and thought it was easier to work than 5160.  If I had to guess I'd say that you were working too cold, but I haven't heard about the air cooling issue Steve mentioned.  When I forged it, I did it in one continuous process, never really letting it get much below a dark red, and certainly not hitting it below an orange.

Normalized, annealed ground and heat treated just fine as well. Give it another shot,  I  think you will like O1 once you get to know it. 

[tdaleh]

Looks kind of like a red short problem . Check out knife making section like Steve said . 

[ytuyuty]

7 hours ago, tdaleh said:

Looks kind of like a red short problem

I was wondering if this was the problem, but as a newbie I had never seen it before.

 

Thank you everyone

[ytuyuty]

Update:

I forged a knife with O-1 no problems. Worked it hot, never let it cool off at all.