Cutting 25mm hardox steel.

[Shox Dr]

Sorry Mike, but when I looked at my records, our shredder has another turn on the teeth. They use one corner at a time. Each corner lasts 8 to 12 months shredding timber 4 hours a day. They are 40mm square and 22mm thick like this:-

View attachment 133986

It has 56 teeth and takes a 50KW motor to run it.

I would take a pic in the machine but its full of snow!

The wood yard had two chippers, one 450mm wide ran a 75hp motor. 4 blades running against a curved screen. Only small <60mm section softwood. The other a huge 12lt v8 drum chipper. 600mm dia x1000mm hammer box. We’d hard face those every 6months. Looked like they’d had rocks through them.

 

[Richard.]

Do you have access to a tig welder? I recently discovered or was told about a process.
I was always aware you could harden steel with such a technique but I wasn’t aware of just how hard you could get things.
A low amp (enough to get a small pool) and with a steep torch angle run the arc up the steel and stop. Allow to cool do another completely cover the steel allowing to rapidly cool between runs. The argon shield and rapid cooling will act as a quench and a very thin hard crust is generated.
Now I was aware of this but what I didn’t know of was done properly you can double the steels hardness. I’m going to be doing some experimenting with this myself.

 

[henry Kadzielski]

Just my two cents. As Richard has said with a TIG there is another process. Using a thin metal tube (say 3mm) you can fill it with a hard facing powder and use it just as if you were tig welding. The steel outer will just melt and you get a very rich hard facing compound which you can spread with the tig arc. The tig arc gives very good control over the weld pool and you can place it just about anywhere you want, oh ant the thickness you like. Haven't done it myself as have not had a need but have seen it done, works great

 

[Richard.]

Just my two cents. As Richard has said with a TIG there is another process. Using a thin metal tube (say 3mm) you can fill it with a hard facing powder and use it just as if you were tig welding. The steel outer will just melt and you get a very rich hard facing compound which you can spread with the tig arc. The tig arc gives very good control over the weld pool and you can place it just about anywhere you want, oh ant the thickness you like. Haven't done it myself as have not had a need but have seen it done, works great

You can save a lot of time and just use flux core hard facing wire under the tig arc. I assume it’s a similar thing to what you were explaining?

 

[henry Kadzielski]

^^ Exactly the same process. However if there is a specific need for alloying elements that are not available with flux cored wire, then the tube method will work.

 

[Mike Wood]

Not got tig or gas.. I was gonna layer stick welds with hard faced rods..

http://www.esab.co.uk/gb/en/products/index.cfm?fuseaction=home.product&productCode=410702

What you think.. dont really want to go tig route just yet..

 

[Richard.]

Bit ott for such small blades. You’ll end up grinding most of that away. It only wants a thin delicate coating at best. If you’ve got mma you could tig weld it with a valved torch and a bottle of pure AR

 

[KemppiFrog]

I recycled a rock crusher (made gravel out of bigger rocks) for pine bark mulch. The electric motor that came with it was 75hp (!!) I pointed out to the client that his electrics would need a serious upgrade including a HT connection with a transformer, as we were out in the sticks. I adapted a Perkins Prima deisel to run it.
Inside were several discs with hinged hammer blades on them. Wacked the big rocks until the bits fell through a grid. Pine bark was obviously not such hard work, but I had the engine spare.
Point being, a 2.2kw motor will be a bit feeble.

 

[Mike Wood]

I recycled a rock crusher (made gravel out of bigger rocks) for pine bark mulch. The electric motor that came with it was 75hp (!!) I pointed out to the client that his electrics would need a serious upgrade including a HT connection with a transformer, as we were out in the sticks. I adapted a Perkins Prima deisel to run it.
Inside were several discs with hinged hammer blades on them. Wacked the big rocks until the bits fell through a grid. Pine bark was obviously not such hard work, but I had the engine spare.
Point being, a 2.2kw motor will be a bit feeble.

It only measures 300mm x 215mm blades being around 120 diam.

A geared 2.2 kw motor geared to say 30 rpm will produce well over 1000nm of torque..

Thats more than enough for wood... plastic and aluminium cans.