X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fmailhost06.isp.att.net ([207.115.11.56] verified) by logan.com (CommuniGate Pro SMTP 5.3.11) with ESMTP id 4651392 for flyrotary@lancaironline.net; Wed, 22 Dec 2010 16:14:47 -0500 Received-SPF: none receiver=logan.com; client-ip=207.115.11.56; envelope-from=bbradburry@bellsouth.net Received: from desktop (adsl-85-147-11.mco.bellsouth.net[98.85.147.11]) by isp.att.net (frfwmhc06) with SMTP id <20101222211410H0600m5ohde>; Wed, 22 Dec 2010 21:14:10 +0000 X-Originating-IP: [98.85.147.11] From: "Bill Bradburry" To: "'Rotary motors in aircraft'" References: In-Reply-To: Subject: RE: [FlyRotary] Re: 13B Turbo Manifold Date: Wed, 22 Dec 2010 16:14:12 -0500 Message-ID: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0003_01CBA1F3.45C0CFE0" X-Mailer: Microsoft Office Outlook 11 Thread-Index: AcuiHLzEdiUW1BXjTMubrJZ8ubHDpgAACZUw X-MimeOLE: Produced By Microsoft MimeOLE V6.0.6001.18049 This is a multi-part message in MIME format. ------=_NextPart_000_0003_01CBA1F3.45C0CFE0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Those SS headers are actually pretty cheap. I wonder what they would = charge to build a header that goes in the wrong direction like is required for tractor planes. =20 =20 Bill B =20 _____ =20 From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Kelly Troyer Sent: Wednesday, December 22, 2010 4:10 PM To: Rotary motors in aircraft Subject: [FlyRotary] Re: 13B Turbo Manifold =20 Ernest you make my head hurt !!...............Now I have to be a "Metallurgist"...............<:) =20 Kelly Troyer "DYKE DELTA JD2" (Eventually) "13B ROTARY"_ Engine "RWS"_RD1C/EC2/EM2 "MISTRAL"_Backplate/Oil Manifold "TURBONETICS"_TO4E50 Turbo =20 =20 _____ =20 From: Ernest Christley To: Rotary motors in aircraft Sent: Wed, December 22, 2010 2:35:58 PM Subject: [FlyRotary] Re: 13B Turbo Manifold Kelly Troyer wrote: > Ernest, > Not sure what you mean by "Welds not cleaned up"...........All I = see on these "TIG" welds is > a slight discoloration at the edge of the weld bead caused by the arc heat.. The first link of a Google search on "stainless steel welding corrosion" = was http://www.mcnallyinstitute.com/04-html/4-1.html From that site: INTERGRANULAR CORROSION All austenitic stainless steels (the 300 series, the types that "work harden") contain a small amount of carbon in solution in the austenite. Carbon is precipitated out at the grain boundaries, of the steel, in the temperature range of 1050=B0 F. (565=B0 C) to 1600=B0 F. (870=B0 C.). = This is a typical temperature range during the welding of stainless steel. This carbon combines with the chrome in the stainless steel to form = chromium carbide, starving the adjacent areas of the chrome they need for = corrosion protection. In the presence of some strong corrosives an electrochemical action is initiated between the chrome rich and chrome poor areas with = the areas low in chrome becoming attacked. The grain boundaries are then dissolved and become non existent. There are three ways to combat this: * Anneal the stainless after it has been heated in this sensitive = range. This means bringing it up to the proper annealing temperature and then quickly cooling it down through the sensitive temperature range to = prevent the carbides from forming. * When possible use low carbon content stainless if you intend to do = any welding on it. A carbon content of less than 0.3% will not precipitate = into a continuous film of chrome carbide at the grain boundaries. 316L is as = good example of a low carbon stainless steel. * Alloy the metal with a strong carbide former. The best is = columbium, but sometimes titanium is used. The carbon will now form columbium = carbide rather than going after the chrome to form chrome carbide. The material = is now said to be "stabilized" They could have used a filler that made post treatment unnecessary, or = they could have annealed it. The link you gave says it is made of T304. Depending on which T304, the carbon ranges from .03 to .08%, so it may = not be an issue at all. -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html ------=_NextPart_000_0003_01CBA1F3.45C0CFE0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Those SS headers are actually = pretty cheap.=A0 I wonder what they would charge to build a header that goes in = the wrong direction like is required for tractor planes.=A0 =

 

Bill B

 

From: = Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Kelly Troyer
Sent: Wednesday, December = 22, 2010 4:10 PM
To: Rotary motors in = aircraft
Subject: [FlyRotary] Re: = 13B Turbo Manifold

 

Ernest you make my head hurt !!...............Now I = have to be a "Metallurgist"...............<:)
 

Kelly Troyer
"DYKE DELTA = JD2" = (Eventually)

"13B ROTARY"_ Engine
"RWS"_RD1C/EC2/EM2
"MISTRAL"_Backplate/Oil Manifold

"TURBONETICS"_TO4E= 50 Turbo

 

 

From: = Ernest Christley <echristley@att.net>
To: Rotary motors in = aircraft <flyrotary@lancaironline.net>
Sent: Wed, December 22, = 2010 2:35:58 PM
Subject: [FlyRotary] Re: = 13B Turbo Manifold

Kelly Troyer wrote:
> Ernest,
>      Not sure what you mean by "Welds not = cleaned up"...........All I see on these "TIG" welds is
> a slight discoloration at the edge of the weld bead caused by the = arc heat..

The first link of a Google search on "stainless steel welding corrosion" was http://www.mcnallyinstitute.com/04-html/4-1.html

From that site:

INTERGRANULAR CORROSION

All austenitic stainless steels (the 300 series, the types that = "work harden") contain a small amount of carbon in solution in the = austenite. Carbon is precipitated out at the grain boundaries, of the steel, in the temperature range of 1050=B0 F. (565=B0 C) to 1600=B0 F. (870=B0 C.). = This is a typical temperature range during the welding of stainless steel.

This carbon combines with the chrome in the stainless steel to form = chromium carbide, starving the adjacent areas of the chrome they need for = corrosion protection. In the presence of some strong corrosives an electrochemical = action is initiated between the chrome rich and chrome poor areas with the = areas low in chrome becoming attacked. The grain boundaries are then dissolved and = become non existent. There are three ways to combat this:

    * Anneal the stainless after it has been heated in this = sensitive range. This means bringing it up to the proper annealing temperature and = then quickly cooling it down through the sensitive temperature range to = prevent the carbides from forming.
    * When possible use low carbon content stainless if you = intend to do any welding on it. A carbon content of less than 0.3% will not = precipitate into a continuous film of chrome carbide at the grain boundaries. 316L = is as good example of a low carbon stainless steel.
    * Alloy the metal with a strong carbide former. The best = is columbium, but sometimes titanium is used. The carbon will now form = columbium carbide rather than going after the chrome to form chrome carbide. The = material is now said to be "stabilized"

They could have used a filler that made post treatment unnecessary, or = they could have annealed it.  The link you gave says it is made of = T304.  Depending on which T304, the carbon ranges from .03 to .08%, so it may = not be an issue at all.


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