Alternate for 8620 steel

[toolmantwo]

I will need to consider an alternate steel for 8620. The part is flat stock .134 thick. We cut it with the Laser and form mild bends, then grind a bevel edge. We heat treat this by .015 -.020 deep case.
What comes to mind?

 

[unclesyd]

The following steels will do what you ar now doing.
ANSI: 3310; 4320; 4620; 4820; E9310
We used a lot of 4820 and 4620 for small carburized parts.
We also used some 3310 at times.

The E9310 was used of much heavier parts.

You will probably have to go with what's available at the present time if you require any quanity.

Come back with a little more information about the desired properties for the end use.

 

[Flesh]

The typical replacement steel is 4120, as seen in the forging industry. It is basically the same steel except it has no nickel. Naturally, this makes it a slightly less expensive alternative. Hardenability will be the same as for 8620, especially in the thickness you are dealing with. The abscence of nickel may slightly reduce its toughness, however this may or may not impact your application.

 

[toolmantwo]

Thanks Unclesyd and Flesh.

OK more about desired properties and the end use.
1. It is part of a hand tool, so we want to avoid the danger to fracture and then any segment that might fly into the user.
2. To be correct the Heat treat is Carburize effective case depth .030-.040 quench temper R15N 89-91 and then later it is shot peened. It must flat within .010 before heat treat and within .040 after.
3. The tool will sever a nail inside a confined area. It will sever by means of one edge beveled traveling to a flat edge opposite. (Pinch off cut).
4. The part is .134 thick, 1-1/4 inch wide by 5-1/4 long. It has pivot and driven holes with tolerances of +/-.002.

Sorry for being so brief before, but I was pressed for time that day.

 

[Carburize]

Is there a specific reason why you want to change from 8620?

 

[toolmantwo]

For Carburize
Yes, they say other steels may be better for availability. We are finding steel to be in short supply here in the USA (Not just 8620)and do not know if this is a temporary problem or long term, or for how long to expect it to be in short supply.

 

[Carburize]

Did your supplier give any indication about which alloys would be more readily available. I suspect if you can list those materials you will get comments on the most suitable for this application.

 

[metman]

With such a small cross-section (.134), you do not need depth of hardening since you have hardly any depth.

1117 is a carburizing grade and although it will not have the tougness of 8620, you end up with such a minimal core if the case is on the high side that I cannot imagine that the core properties can make that much difference as long as it has a modicum of toughness which the 1117 will provide. However, I am not sure if 1117 is available in flat stock, otherwise it is readily available.

Jesus is THE life,
Leonard

 

[TVP]

metman,

1117 is not generally available in flat products. Also, I am not sure that I understand your statement about core properties-- at the maximum depth the case is still only ~ 30% of the cross-section. Core properties will still be important.

 

[toolmantwo]

Thanks people. To be more clear the major load is applied in the direction of the 1-1/4 width, with only a slight side load to the .134 thickness. The tool resembles a small bolt cutter that has compound leverage. My "Best steel suppler" has yet to return my phone call, so not much has been proceeding to date. What are your thoughts about stainless steel like 440C (UNS S44004)? I will check out the above mentioned steels from your replies.

 

[metman]

TVP,
I was looking at it from the other end, meaning at max case the core is only 40% of the section which now seems more substantial in terms of percentage. I guess .04 just does not seem like much help in terms of the application which makes me think in a different direction and will address below.

toolmantwo,
Your total material cost for the cutter will be minimal because of size unless you are producing these in large quantities. My earlier suggestion was slanted toward economy of material biased by the existing material choice. I suggest you consider S7 Tool Steel. This will provide toughness, edge retention and the reduction of cost for heat treatment by eliminating carburizing will offset at least some of the material cost.


Jesus is THE life,
Leonard

 

[EdDanzer]

Can you induction harden the cutting edge?
If so there are many other materials that may work and reduce manufacturing cost. You may be able to use a lower hardness and get adequate life.
One problem with sharp edge tools when heat treating is air cooling of the fine edge between the furnace and quench tank. The result is a soft edge a few thousands thick that dulls quickly.

 

[toolmantwo]

OK Now I have some more information.
The steel supplier has suggested using 4130. It is avaiable, but he was not sure we can case harden the part or if direct heat treating will give us the toughness. He recommended that we reach the heat treat people for input. He is an advocate for trial and error. My manager is not that type to go only on trial and error because the attempt may not yield any favorable results.

EdDazer
Our current heat treat source does not want to induction harden anything anymore, because it has large variables and the staff is not great. They have tons of turnover of help, thus any hand operations like induction is not desired by them. I guess we could try a difference source.

Metman
I would like S7 in any trial.

All
Please review the 4130 for a alternate and what we might expect.
Thanks

 

[alexit]

If you are changing because of material shortage 4130 is going to act similar to 8620 after carburizing.

If you are changing to improve, what is optimum? We make many parts from 8620, but when we need more toughness we use D2 tool steel, if we need corrosion-resistance we use 440C. These changes for us also alter the heat-treatment, both of these can be through-hardened to similar values as the surface of carburized 8620 (50-60Rc.) Our findings have been that D2 is very abrasion resistant (very hard to grind!) and 440C is softer but better corrosion-resistant and still very tough.

 

[EdDanzer]

What is the part used for? When choosing a material the application may be a deciding factor.
As to induction hardening,

http://www.mfgquote.com

is a good place to get quotes on different processes.