- Discount Offers
- Stainless steel pickling pastes15 items
Pickling pastes are only used after welding for th...
- Stainless steel cleaning and maintenance12 items
Products in this section are for removal of Iron (...
- Weld Cleaning and Marking machines22 items
Electro-chemical machines for the fast removal of ...
- Stainless Steel Identification and Test kits10 items
ELECTRO-CHEMICAL TESTING EQUIPMENT for alloy ident...
- Non Destructive Testing products (NDT)17 items
Quality Non-destructive testing products for liqui...
- Aluminium cleaners7 items
We have developed a range of products designed to ...
- General Metal cleaning and maintenance products12 items
Aluminium, Copper, Nickel, Steel & Stainless Steel...
- Dry Ice Cleaning7 items
Innovative cleaning system for fast removal of sur...
- Tungsten welding electrodes (TIG)1 items
High quality, European manufactured, tungsten elec...
- Tungsten electrode grinders (TIG)4 items
A range of grinders for sharpening tungsten electr...
- Specialised Welding and Fabrication products8 items
A range of products which are designed to assist f...
- Metal powder spraying torch1 items
Torches & powders for build up and repair of metal...
- Silver and Copper brazing alloys6 items
High quality, European manufactured, brazing alloy...
- Triten Wear Products1 items
Custom manufactured plates for wear resistance. ...
- Material Safety Data Sheets1 items
MSDS for our products. Unfortunately we are unabl...
Articles / News
- 28 Sep 2016
How to chose a weld cleaning machine
- 27 Sep 2016
Passivation of Stainless Steel
- 26 Sep 2016
Pickling of Stainless Steels
- RSS Feed
- More >>>
Ferroxyl Test for Free Ironposted on 25 September 2016 | posted in Stainless steel
We have introduced a new kit for the Ferroxyl Test for Free Iron, outlined in ASTM A380-06, section 7.3.4 & A967-05 Practice E.
It is a very highly sensitive & hazardous test and should be used only when traces of free iron or iron oxide is "objectionable". Personnel familiar with its limitations and hazards should only be permitted to use this test method.
It consists of two solutions, A & B, which contain nitric acid and potassium ferricyanide. The potassium ferricyanide can emit lethal fumes if it is exposed to concentrated acids, or heated to decomposition. The solutions are combined before use as the mixture has an active shelf-life of approximately 24 hours.
A filter paper is soaked with equal amounts of each solution and applied to the surface. The paper turns dark blue within 15 seconds when iron is present.
It is not recommended for use on products destined for use in food, medical or pharmaceutical unless complete removal of the cyanide solution can be guaranteed.
An alternative is our Copper Sulphate or Passivity test kit which will give a red/pink result when in contact with Iron. The chemicals used in these tests are not hazardous.
Carbon steel can cause contamination of the stainless steel even if airborne particles come into contact with the passive layer of chromium oxide. Very few fabricators have the capability to fabricate in a clean room environment. There are many ways to remove free iron and free iron oxides by using for example, Antox 75E ( a phosphoric acid solution) or EWP 51 (Citric acid).
A ferroxyl test is a test done only to "detect" contamination. Once contamination is detected, then a removal procedure is carried out.