It is currently Tue Nov 21, 2017 5:16 pm Advanced search

Plasma cut /gouge and cast iron

Metal cutting - oxyfuel cutting, plasma cutting, machining, grinding, and other preparatory work.

Plasma cut /gouge and cast iron

Postby olek » Sat Jun 17, 2017 7:48 am

Hello,

I did read that plasma cutting do deform the less the pieces if compared with other crude methods.

I wonder if on cast iron it will generate less white hardened iron than cutting disk ?

I am wondering if the process, by immediate ejection of the melted metal, do not allow a less deep heat penetration, or some sort of cooling because air replace the metal.

Do you have some informations ? I will ask one or 2 specialized compagnies I think I will have an answer, unless it is evident in some way.

Gouging electrodes do not burn the metal as much as plasma, I was said.

Regards

Also, gouging electrodes are proposed for iron weld solutions. (Not arcair but I don't know for sure )

I use carbide mill bits for iron but if I want to get rid of a hardened Zone to replace it with FeNi metal what would be the best process ? (Carbide drills will just wear off)
Pianos , restorer and tuner
Dedicated to learn welding since april
slowly learning ;) not complaining of doing beads and beads
pro inverter PROGYS 200 FV PFC CEL+tig lift
OA Oxyflam 1000 cutting and welding gas torch
olek
Guide
 
Posts: 189
Joined: Sat Jun 03, 2017 4:07 pm
Location: France

Re: Plasma cut /gouge and cast iron

Postby Otto Nobedder » Sat Jun 17, 2017 9:41 pm

Olek,

Perhaps with this question you would do well to post it in French, and allow one of or Quebecois members to translate? I'm having difficulty understanding the question.

Steve
User avatar
Otto Nobedder
Weldmonger
 
Posts: 8404
Joined: Thu Jan 06, 2011 11:40 pm
Location: Near New Orleans

Re: Plasma cut /gouge and cast iron

Postby olek » Sun Jun 18, 2017 8:21 am

Thank you Otto.

Sorry for my limited English. I ask if it may be an option to use a cheap plasma cutter to open cracks in iron.

If it burn the iron , obviously it is not.

Thanks

Isaac
Pianos , restorer and tuner
Dedicated to learn welding since april
slowly learning ;) not complaining of doing beads and beads
pro inverter PROGYS 200 FV PFC CEL+tig lift
OA Oxyflam 1000 cutting and welding gas torch
olek
Guide
 
Posts: 189
Joined: Sat Jun 03, 2017 4:07 pm
Location: France

Re: Plasma cut /gouge and cast iron

Postby olek » Mon Jul 03, 2017 4:41 pm

I have another question

Is there a difference when using a plasma torch , between pushing, and pulling

Some pro just wrote that it is better to push (to avoid melted metal to jump on the electrode I think he said )

The torch is hold straight at 90 degrees is not it ? an angle is created because of the travel speed that is all, so I do not see where a difference can be when manually cutting, between drag and push (this is for a contact torch)

Thanks
Pianos , restorer and tuner
Dedicated to learn welding since april
slowly learning ;) not complaining of doing beads and beads
pro inverter PROGYS 200 FV PFC CEL+tig lift
OA Oxyflam 1000 cutting and welding gas torch
olek
Guide
 
Posts: 189
Joined: Sat Jun 03, 2017 4:07 pm
Location: France

Re: Plasma cut /gouge and cast iron

Postby homeboy » Mon Jul 03, 2017 7:31 pm

When cutting a straight cut with a guide I normally drag because it slides easier than pushing. Mine is a drag or contact tip also. When cutting irregular shapes whether flat or profiled just keep the torch at 90 degrees to the work and glide it around keeping the tip as close as possible to the work piece. As for direction it shouldn't matter, just cut in the direction that is most comfortable for better control. I am right handed so I usually cut from right to left when cutting freehand for better visibility. There are some good videos perhaps on You Tube which may help. :D :geek:
homeboy
Guide
 
Posts: 175
Joined: Mon Dec 19, 2016 11:52 pm

Re: Plasma cut /gouge and cast iron

Postby jimcolt » Wed Jul 05, 2017 7:49 am

If using consumables designed (shielded, proper arc length) for drag cutting (for hand cutting) then the best cut quality is achieved with the torch dragging directly on the material and with the torch perpendicular to the material. Whether you push or pull does not matter....whatever is comfortable and provides the most fluidic motion. A drag shield eliminates stiction allowing for smooth motion and smooth cut edges. Jim Colt Hypertherm
jimcolt
Workhorse
 
Posts: 52
Joined: Fri Apr 24, 2015 12:11 pm
Location: New Hampshire, USA

Re: Plasma cut /gouge and cast iron

Postby Artie F. Emm » Wed Jul 05, 2017 11:34 am

Cast iron is outside my experience, but I'll jump in to possibly provide some clarity.

Olek, please check me: it sounds like Olek is repairing a crack in cast iron, and asking what method he can use to grind out the crack. He uses the phrase "white hardened iron" (which returns no hits in a google search), seeming to indicate a work hardened or heat affected zone caused by a grinding disk that he'd like to minimize.

Does the "white hardened iron" ring a bell for anyone? Is plasma cutting or arc gouging a good approach to crack repair? Can you manually control these processes enough to remediate a crack? I've only ever heard of drilling the ends of the crack and using a grinding disk.
Dave
aka "RTFM"
Artie F. Emm
Weldmonger
 
Posts: 629
Joined: Thu Jul 24, 2014 7:53 am

Re: Plasma cut /gouge and cast iron

Postby olek » Wed Jul 05, 2017 11:57 am

Hello

Thank you for trying to understand me.
Yes grey cast iron when hardened by strong heating have much more embedded carbon molecules, I find "pale iron" or wear resisting iron , but also white iron . on the internet.

That is a state of the metal . A reversible one but I cannot do that process.(the iron part I work on is very large and long)

I just wonder if plasma cutting is creating a smaller HAZ than gouging electrodes.

For my repair I used milling with pneumatic tools so to obtain
. Minimal heat. But I am interested for the bext repair.
The gouging "arcair' electrodes make a U shaped canal very fast.

Best regards
Last edited by olek on Tue Jul 11, 2017 4:14 pm, edited 2 times in total.
Pianos , restorer and tuner
Dedicated to learn welding since april
slowly learning ;) not complaining of doing beads and beads
pro inverter PROGYS 200 FV PFC CEL+tig lift
OA Oxyflam 1000 cutting and welding gas torch
olek
Guide
 
Posts: 189
Joined: Sat Jun 03, 2017 4:07 pm
Location: France

Re: Plasma cut /gouge and cast iron

Postby Fly » Sun Jul 09, 2017 11:39 am

If your talking about repairing a crack I have done that many times. I drill a small hole
at the ends of the crack. I vee the crack some by grinding. I then preheat the casting
& then braze it. It has always worked for me.

Fly
Fly
Active Member
 
Posts: 40
Joined: Thu Jan 24, 2013 10:07 am

Re: Plasma cut /gouge and cast iron

Postby olek » Sun Jul 09, 2017 4:02 pm

I am not equiped for bronzing. And to heat at a sufficient temperature also.

I did read that it was better to keep the boring(s) open. As the part that cracked can be fragile the holes( if no etancheity problems), are relieving stress so they are considered a security.

I did read that on a manual for repairs of large constructions,(bridges) big machinery' as caterpillar and so on pieces under work load stress.

I tested plasma and it is hardening iron as hell, grinding if compared leaves the metal soft enough, no hardening that I could see testing with a file
Pianos , restorer and tuner
Dedicated to learn welding since april
slowly learning ;) not complaining of doing beads and beads
pro inverter PROGYS 200 FV PFC CEL+tig lift
OA Oxyflam 1000 cutting and welding gas torch
olek
Guide
 
Posts: 189
Joined: Sat Jun 03, 2017 4:07 pm
Location: France

Next

Return to Metal Cutting