Derustit 1234
Pickling solution
Descripción y aplicaciones
The most widely adopted chemical method for removing oxidation from stainless steel is by immersion of the material in a special pickling solution.
DERUSTIT Pickling Solution 1234 is intended for this purpose and has been carefully formulated to remove welding oxides and heat discolourations with minimal effect on the stainless steel itself. Other contaminants such as light ferritic oxides and deposits are also removed during the pickling process.
Instrucciones
DERUSTIT Pickling Solution 1234 is intended for use on the Austenitic range of Stainless Steels, Nickel and Nickel Alloys, Copper-Nickel Alloys and special materials such as Inconel, Incoloy, Hastelloy etc. Of course it is free of Hydrochloride acid.
Pre-treatment
Any oils, lubricants or grease etc. on the surface will impair the effectiveness of the pickling action, therefore degreasing before immersion is essential. A suitable alkaline degreasing solution can be prepared using DERUSTIT Pickling Degreaser 3023 or DERUSTIT Cleaner 1622. It is recommended that all items being welded and/or heat treated should be degreased prior to such operations in order to avoid any problems arising from carbon being „burnt“ into the surface. Similary any marking ink, paint, cast marks etc. should also be removed. The components should be cold prior to immersion in Pickling Solution 1234.
Using the product
DERUSTIT Pickling Solution 1234 is supplied as a concentrate requiring dilution 1:1 by volume with clean water in a plastic or plastic lined tank fitted with adequate fume extraction. Suitable plastics for use on the tanks are UPVC, Polyethylene, Polypropylene and PVDF. Quotations for the supply of tanks for your specific application can be given on request. DERUSTIT Pickling Solution 1234 is supplied in 35 kg drums having a volume of approx. 30 litres. Thus one drum will produce 60 litres of ready to use pickle. The volume of pickle should be at least 25 litres per m² of surface area being treated in order to prevent excessive heat being generated.
Pickling time is dependent upon the nature and degree of oxidation requiring removal, as well as the solution. The following reference values are based on an operating temperature oc approx. 293 K (20° C):
Stabilized Stainless Steel Alloys e.g. material 1.4541, 1.4550, 1.4571
fresh to 1 week old bath 20 - 30 minutes
1 - 4 weeks old bath 40 - 60 minutes
older baths up to 2 hours.
Nonstabilized Stainless Steel Alloys e.g. material 1.4301, 1.4306, 1.4401, 1.4435
fresh to 1 week old bath 10 - 15 minutes
1 - 4 weeks old bath 20 - 30 minutes
older baths 1 - 2 hours.
With use the solution will, naturally, become depleted and due to „drag out“ the level in the tank will fall. Any topping-up or replenishment should be carried out using the concentrate DERUSTIT Pickling Solution ie. undiluted.
After pickling the components should be thoroughly rinsed free of all solution using clean cold water. Whilst pickling loosens heat generated oxides it is generally necessary to forcibly wash or „rub off“ the residue scale. Mains water is normally satisfactory, but the use of high pressure (150 bar) cold water washer can be of great benefit in terms of speed of operation and efficiency.
Post-treatment
A clean stainless steel surface will generate a protective oxide layer in free air. The formation of this „passive layer“ can be accelerated by chemically passivating with DERUSTIT Passivating Solution 2016. Effluent treatment Effluent rinse water resulting from using DERUSTIT Pickling Solution 1234 should be neutralised prior to disposal in accordance with local authority regulations.
Safety precautions
DERUSTIT Pickling Solution 1234 contains Hydrofluoric and Nitric acids and the precautions normally taken when working with acidic solutions should be observed with this product. Protective clothing such as rubber gloves and goggles should be worn. More comprehensive safety details are available on the appropriate DERUSTIT safety data sheet.
Please note
The information contained in this data sheet is given to the best of our knowledge and is based upon practical and laboratory tests. Our technical service department is willing to offer advice and handling, application and process techniques.
We are also able to undertake cleaning, pickling and passivating work either at our Dietzenbach works or on-site.