Dear Franco DiFolco and Others,
A better tool for analyzing steel is the spark OES or XRF but we work
with what we have.
The primary alloying elements, which I assume is what elements you
will be looking for are as follows with ranges you can expect from an
Aluminum 0-2% (alloy 17-7)
Carbon 0-1.5% (low carbon -high carbon steel)
Chromium 0-18% (higher chrome for stainless steel)
Nickel 0-12 i.e., 18/10 stainless steel cookware is 18% Cr 10% Ni
Lead 0-0.4 often added for ease of machinability
These are the common alloying elements. You will find some others at
lower levels which are called tramps (they go along for the ride).
I may have left elements some out but this should get you program
going. The major players are Fe,Cr,Mn,Ni,C, P, and S. With this
profile you can pretty much ID the alloy.
As far as dissolving steel I use aqua regia for as a universal steel
acid. Not sure how it would work for aluminum, silicon, and carbon
which may form oxides.
Of course, Fe is notorious for interferences. I suggest you use
several different wavelengths, dilutions, and internal standards in
you analysis until you get good experience with this group of samples.
The Unified Nubering System (UNS) is widely used in the US to ID
alloys.Society of Automotive Engineers, Inc. 400 Commonwealth Drive,
Warrendale PA 15096-001. 412 776-4841. ISBN 1-56091-314-2. ASTM
DS-56E. There are many others ....
The ASTM index may also be of help as well as foundries to supply you
with specs. for the different alloys (300 series, 1000 series, ....).
Question: Can you use a magnet to differentiate stainless teels from
Answer: Sometimes. 300 series stainless is NOT magnetic while mi8ld
steels are. 400 series are somewhat magnetic. Why ???? Idonno.
This is a quicky trick to check for shop mixups (is it or isn't it
stainless ?) I learned.
______________________________ Reply Separator
Subject: Re: Digestion Method
Author: "Robert Thomas" <SMTP:[log in to unmask]> at chicago1
Date: 11/30/1999 9:23 AM
Franco DiFolco wrote:
> Hello everyone
> Does anyone know where I can find a method for the digestion of steel. We
be analysing for its major components as well as for trace impurities using
ICP-MS and AA techniques. Published methods would be preferred, but I would
interested in hearing from people that are doing this type of analysis.
> Thanks in advanced
> Franco DiFolco
> CSA International
> Toronto Canada
Having worked for 14 years as an analytical chemist in the steel
industry, I can tell you that steel comes in many different grades - all
with their unique chemical composition. From plain carbon steel with
less than 0.1% carbon to high temperature alloy steels with % levels of
tungsten, titanium and molydenum. There is not one acid or acid mixture
that will dissove all the different types. Each grade of steel presents
its own unique challenge when trying to get it into solution. I would
need to know the type of steel you are analyzing, before recommending a
digestion method. You can send me a private e:mail with more details if
4615 Sundown Road
Gaithersburg, MD 20882
e-mail: [log in to unmask]