Forging / sanmai welding CPM3V?

PEU

PEU

Gaucho Knifemaker
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Aug 6, 2006
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Well its not about CPM3V but I tought I will get more replies if I ask about a known steel. The story goes like this:

I found a piece of Uddeholm Vanadis 4 Extra, which is very similar to CPM4V (I wonder where Crucible got its inspiration :rolleyes: ) and with a friend we want to make it the core of a couple of sanmai billets (AISI 420 on the sides)

When he asked me about the forge temperature, I found none, looked at CPM3V, CPM4V, Z-Wear datasheets and none lists this temperature, so there must be a very good reason not to forge, one may be that these steels are a royal PITA to forge to begin with.

But thats where I am right now, I would like to know this temperature and/or any precaution to have to do what we want to do. Thanks in advance.


Pablo
 
Let me start by saying I have zero experience with 3v. However looking at its chemistry, I would say that it would need to be forge welded without any oxygen present (due to the formation of chrome oxides). Mig welding around all edges of the san mai billet will take care of that. As to forging, the chemistry does not scream out to me that it cannot be forged but with alloyed steels you run into forging temperature issues like red hard, red short, crumbling ect. If you cant find any information on the temp ranges you are going to have to experiment.

I have found that the easiest way to be successful forge welding significantly different steels together is to start with the billet about the width of the finished dimension needed for the blade, then forge only on the flats of the san mai and not on the edge. The steel has a tendency to sheer when hit on the edge or even pressed on the edge. Your results may vary but these are just a few things I have noticed forging stainless san mai.
 
John, I once experimented with 420-D2-420, as you said, with the flattened and clean surfaces I welded the entire perimeter and had various problems: to much pressure and temperature, the D2 liquified like mayonnaise and both sides almost squizzed it, very dangerous moment. Other had crystallized zones, after hardening/tempered they were brittle.

Thats why I'm asking, maybe someone already did it and can help with tips.


Pablo
 
Yes :D But there are no talking about temperatures/procedures there.


Pablo
 
Hmm, so a decade has gone by, has anyonbe foun the solution to OP-s question
PEU said:
Yes :D But there are no talking about temperatures/procedures there.


Pablo
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Currently the stock material of Vanadis 4 Extra that i have comes too thick would really want to know at what temperature and if i can hammer it down to a more decent size.
 
koduu said:
Hmm, so a decade has gone by, has anyonbe foun the solution to OP-s question


Currently the stock material of Vanadis 4 Extra that i have comes too thick would really want to know at what temperature and if i can hammer it down to a more decent size.
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Take it up to bright yellow heats and try a cupon. Forge it a good bit, all at that bright yellow heat. Heat treat, and then etch the peice. Destructively test to find microfracures. If none are found, great, if you have problems, try it hotter.
 
Do you have a press or power hammer? I once tryied forging 3V and it’s amazingly resistant to moving at tempature. At tempature it feals like like your forging cold steel. If at any time it feals easy to forge its to late and you done messed it up. If you go to hit it just comes apart. I have thought about trying it agian now that I have my bigger press. But I don’t know if I really want to inflict that kind of torture on my self agian.
 
No, I dont have a power hammer so I ant really test that.

I was wondering if I need to do something special to avoid decarburization of the steel while I am forging and heating it. Also since i have a charcoal forge and an electric heat treatment oven, which one would be better to avoid decarb?
 
Your going to build up a ton more scale and decarb in a oven then a forge. This is assuming your forge is running properly. But still it’s going to be a rough road to forge 3V by hand. And a charcoal forge is going to make it even harder. All it takes is forging it to hot once and it will come apart. I would equate forging 3V at the right tempature is as hard as forging cold mild steel. Maybe not that extreme but it sure feals like it when you give it a solid strike with a 4Lb hammer and it just dents. I wish you luck
 
Hot ductility of 3V and Van 4 alloys is between roughly 1900 and 2050. Narrow band to work with but above and below will give you problems. Matching these grades with 400 stainless sides can set you up for a potential galvanic corrosion situation so rust prevention will be critical when you are done.
 
These high alloys are referred to as “super steels” for a reason. Forging into Sanmai would not add anything. And, in fact I believe the heating and pounding would only serve to drive Carbon out of the steel. Actually weakening the composition, I believe.
 
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One Armed said:
These high alloys are referred to as “super steels” for a reason. Forging into Sanmai would not add anything. And, I’m fact I believe the heating and pounding would only serve to drive Carbon out of the steel. Actually weaken it.
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Hu,?
Wouldn’t less carbon make it tougher?

I’m not of the belief that forging inherently makes steel better. But I also don’t think it weakens it. I read an article alittle while ago talking about forging and the claims of it making the steel better. Thy actually said that forging is more beneficial to the higher aloy steels like D2 then the simple carbon steels.
 
I wasn’t referring to the toughness of the steel. I used the word COMPOSITION. Weakening, as in, “changing” the relationship of the various elements to one another.

No..high alloy steels are in no way made better by forging. And several can’t be, as they won’t move under the hammer. All the truly high performance knives are made via stock removal.
 
One Armed said:
I wasn’t referring to the toughness of the steel. I used the word COMPOSITION. Weakening, as in, “changing” the relationship of the various elements to one another.

No..high alloy steels are in no way made better by forging. And several can’t be, as they won’t move under the hammer. All the truly high performance knives are made via stock removal.
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It has been proven that forgings are tougher. Not by knife guys but by manufacturing experts. Steel is steel, even high aloy super steels are made into sheets by forging. Here is a little quote from one such expert.

Forging refines the grain structure and improves the physical properties of the metal, so that the grain flow can be oriented in the direction of principal stresses encountered in actual use. Physical properties such as strength, ductility, and toughness are much better in a forging than in the base metal.

As steel bars are rolled, the grain structure within the steel is forced to flow along the centerline of the bar. When a standard or custom forging is produced from the bar, this inherent grain flow bends to follow the contour of the forged shape, thus producing a superior part. Any machined part, whether produced from bars or plate, will, by definition, cut through part of the grain flow. Just about any metal can be forged. However, some of the most common include: carbon, alloy and stainless steels; very hard tool steels; aluminum; titanium; brass and copper; and high-temperature alloys which contain cobalt, nickel, or molybdenum.

The forging process can create parts that are stronger than those manufactured by any other metalworking process. This is why forgings are almost always used when reliability and human safety are critical.
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Oh!!! Yeah I forgot! That’s why the super mystical Japanese swords of centuries ago, could cut through anything! It’s because of the intensified super magic forging power of awesomeness!!:D

Uhg! Take some time and learn about steel & alloy. This is referring to parts made by forging vs CASTING! Little lesson for you....since I’m a gunsmith/firearm’s builder. Several of the firearms I build use RECEIVERS.... sometimes an upper and a lower. Forged receivers are always preferred to CAST receivers, as the cast can have air pockets, slight imperfections and almost microscopic deviations which can result in cracking.

But NOW....the new thing is BILLET RECEIVERS. These are CNC machined from a solid block(billet) of material, in really expensive 4-axis machines. Some are now saying these BILLET units are even stronger than their forged counterparts.

High alloy knife steel, as we get it in billets/sheets whatever...is NOT cast! It is hot rolled to, and then sheared/cut to sizes we buy. Guess what the hot rolling of the steel is??? FORGING!

And that ends the lesson for today!
 
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