Wednesday, July 28, 2010

RE: [MW:6162] why plsama cutting in ss

Dear Friends

Basically  Good curability depends upon   the melting point of oxide formed during cutting , and it should have lower melting point than adjacent base metal 

i)                     To explain in simple word  --Incase of CS  ,when you are cutting with oxy acetylene  fuel , Initially the outer orifices  of cuttogen /nozzle preheats the area to be cut which oxidizes the Fe  in the vicinity of cutting edge , later on you inject the oxygen through central orifice therefore the further oxidation,creates the  exothermic reaction which increases the temperature in  the creft (Cut),  resulting in to  melting of iron oxide  and forms the creft and causes the cutting action , The creft  side wall having thin  oxide layer    which is having lower melting temperature than adjacent base metal. The molten slag in the cut being forced out by oxygen lance and this way the   cutting operation takes place.

ii)                   In case of CS, the  melting temp of Oxidised slag/iron  is lower than melting point of Iron therefore  CS is having good cutabilty than SS or high carbon steel

iii)                 Incase of SS – if you use oxy acy fuel to cut , The Cr in SS gets oxidized and melting temperature of Cr Oxide is much higher than actual SS base metal therefore you can not cut the SS , aluminium, C.I.and Non ferrous  with GAS fuel due  to its poor cutablity  

Regards

 

Hegde P.B.

 

 

From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of ali asghari
Sent: Wednesday, July 28, 2010 9:28 AM
To: materials-welding@googlegroups.com
Subject: Re: [MW:6155] why plsama cutting in ss

 

because the speed of cutting& concentration of heat in plasma  is more than oxyacetelene cuttng, therefore cooling rate is most&  St.St isn't sentisized.

On Tue, Jul 27, 2010 at 6:10 PM, mijin <mathew.mijin@gmail.com> wrote:

why we are using plasma cutting in stainless steel instead of
oxyacetelene cuttng.please give me a reason...

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