This document provides information on cleaning, passivating, and electropolishing stainless steel. It discusses the importance of having a smooth, contaminant-free, chromium oxide-coated surface for corrosion resistance in stainless steel. Welding can introduce contaminants, so pre-and post-weld cleaning is important. Chemical treatments like pickling and passivation can remove weld residues and contaminants to restore the protective oxide layer. Electropolishing further enhances corrosion resistance by removing any remaining free iron and contaminants to fully repassivate the surface. The Weld PostCleener system is introduced as a portable, chemical-free method that uses electricity to efficiently clean and electropolish stainless steel.

1. CLEANING ............. . PASSIVATING ........ . ELECTROPOLISHING . OF STAINLESS STEEL

2. PRESENTATION EXPLAINING the
WELD POSTCLEEN SYSTEM
………. its FUNCTIONS, ADVANTAGES, and
STAINLESS STEEL

3. ABOUT STAINLESS STEEL

4. What is needed for a STAINLESS STEEL surface?
* A smooth surface so contaminants are not trapped or allowed to concentrate.
* A surface free of dirt and grease so the chromium oxide has air access.
* A thick, continuous chromium oxide film.

5. Welding
•PRE-Welding surface preparation can improve the amount of contaminants produced during welding.
•Welding itself is not generally the problem.
•The issue is pre and post-weld cleaning…….
• - Minimize preparation contaminants
-Remove heat tint
-Remove layer with lower Cr

6. Weld Contaminants
Metal cutting fluids.
Shared metal cutting / grinding equipment.

7. Chemical Treatments
Pickling
Remove weld heat tint and scale.
Remove embedded iron.
Passivation
Remove light surface iron contamination.
Immediately forms the protective oxide film.
Enrich the surface with chromium .

8. •Pickling acids remove heavy weld scale, heat tint, the depleted chromium layer.
HF based pickling agents attack stainless.
Etching:
PICKLE PASTE is a OH&S issue.
Hydrofluoric acid is a schedule 7 poison.

9. • Steels containing more than 11% Chromium are capable of forming an invisible, inert or passive, self-repairing oxide film on their surface.
• It is this passive layer that gives stainless steels their corrosion resistance.

11. PASSIVATION.........
Pas.si.vate
To render a metal less liable to corrosion by coating the surface with a substance, such as an oxide.
Passivation also is accomplished by ...................
Electropolishing.

12. Passivation
The passivation of stainless steel is performed when free iron, welding scale, welding tint, iron particles are removed from the surface to allow the protective oxide layer to form.
Increases the Chromium content of the surface.

13. ELECTROPOLISHING
is a electrochemical process that is a......
SUPER PASSIVATOR
of stainless steel and results in a
more passive surface.
This is typically done to remove any "free- iron" from the surface of the metal, which enhances the corrosion resistance of the stainless steel surface and accelerates the re-formation of the passive layer.

14. Electropolishing
The electropolishing process smoothes and streamlines the microscopic surface of a metal object.
As a result, the surface of the metal is microscopically featureless.

15. ie. a brighter surface.
Roughness typically decreased by 25 to 35%.
Courtesy of MME Surface Finishing
Electropolishing removes microscopic high points or "peaks" much faster than the corresponding rate of attack on the
micro-depressions or "valleys."

16. Smoothness of the metal surface is a very advantageous effect of electropolishing.
During the process, a film of varying thickness covers the surfaces of the metal.

17. Electropolishing
a valuable alternative.....
To Pickling paste
( Hf + Nitric )
AND
Nitric acid for Passivating

18. Can electropolishing improve corrosion resistance ?
Yes because:
Surface is smoothed and polished.
Sharp edges are removed.
Burrs are removed.
Embedded iron particles are removed.
A Completely passivated surface is formed.

20. Handrail Corrosion
Darling Harbour , Sydney
Grinding marks
Embedded iron
611
Should be
SMOOTH
Should be
CLEAN

21. A summary in a picture...
0.46,
0.62,
0.68
μm
316 handrails at
Bondi Beach
Tea stained – No4 finish,
exposed horizontally
Not tea stained – pickled No4
near the weld, treated when
the weld was pickled.
Not tea stained – a high polish finish .
Stained – the weld was not
pickled well enough, there was
low chromium layer left in the
recesses
0.37,
0.39
μm
Ra
Ra
Ra.......measure of surface roughness

22. STAINLESS FUME HOOD with CARBON STEEL clamping rings.
PRE and POST CLEANING stages using the GWC SYSTEM.

23. LITTLE PARA FLOOD GATES PRE - CLEANING

24. LITTLE PARA FLOOD GATES POST CLEANING – project completed

26. Manufacturer of the ........
STAINLESS LIFE SOLUTIONS
YOUR

27. WP........ WELD POSTCLEEN
THE POWER SYSTEM
Pure DC , smooth, stable system

28. WP SYSTEM KIT
WP 1000

29. WP SYSTEM KIT
WP 2000

30. CARBON FIBRE BRUSH RANGE
WIDE BRUSH RANGE
50 mm WIDE SMALL
100 mm WIDE SMALL
30 mm WIDE MEDIUM
50 mm WIDE MEDIUM
50 mm WIDE LARGE
100 mm WIDE LARGE
ROUND BRUSH RANGE
SMALL ‘O’ RING
MEDIUM ‘O’ RING
LARGE ‘O’ RING
30 mm ROUND
SMALL SLEEVED
MEDIUM SLEEVED

31. For best results a supply of clean, ripple-free DC power must be available to drive the process.
The DC power must be applied at the correct voltage and current for best results.
refer to.....
WELD POSTCLEENER specifications.
THE WELD POSTCLEEN SYSTEM

32. HOW the WP – WELD POSTCLEEN can help you.
1/ FAST EFFICIENT CLEANING AND ELECTROPOLISHING OF
STAINLESS STEEL PRODUCTS WITH THE HIGH POWER OF SYSTEMS AVAILABLE.
2/ NO MORE USING DANGEROUS TOXIC PICKLE PASTE AND NITRIC
ACID CHEMICALS THAT ARE ENVIROMENTIALLY HAZARDOUS
AND A MAJOR OH&S ISSUE.
3/ MOST POWERFUL SMALL PORTABLE SYSTEM ON THE
WORLD MARKET.
4/ POWER SUPPLIES FULLY ADJUSTABLE FROM 100 watts TO 1000
watts WITH SINGLE SYSTEMS.
200 watts TO 2000 watts WITH THE DUAL SYSTEM.
5/ DUAL SYSTEM CAN BE SPLIT TO OPERATE AS TWO ISOLATED SYSTEMS.

33. 6/ CLEAN INTO THE TIGHT CORNERS OF STRUCTURES WITH THE WIDE
RANGE OF FLEXIBLE BRUSHES.
7/ EASY REMOVAL OF TEA-STAINING.
8/ LARGE SURFACE AREA CLEANING / PASSIVATING OR
POLISHING WITH THE LARGER BRUSH SIZES AVAILABLE.
9/ PORTABLE FOR ONSITE WORK.
10/ EXTEND THE RANGE OF ELECTROPOLISHING BY USING THE
ADVANCED DESIGNED BRUSHES.
11/ POWER SUPPLY VERY RELIABLE.............100% DUTY CYCLE.

34. WP SYSTEM KITS
WP 1000
WP 2000

36. COOPERS BREWERY
CONTRACT ENG.
TYNBELL SHEETMETAL
LAI INDUSTRIES
TOOLPAK ENG.
WESS HIRE
SMITH SNACK FOODS
BHP BILLINTON.......... OLYMPIC DAM
AUSTEK ENG.
RAG ENG.
WATSON FITZGERALD
DMK ENG ............... Mt GAMBIER
MAYFIELDS LEIGHTONS
WYNNS WINERY..........COONNAWARA
LAI INDUSTRIES
ALSTOM THERMAL SERVICES .. VIC.
ZEST VISION
JOHN PERRY ENG......... VICTORIA
HAYWARDS FAB......... TASMAINIA
WATERNISH
SEALECK PTY LTD
K J FABRICATION
TRUSHAPE ENG.
ARGARS IND.
EXTREME FAB.
CUSTOMS SOLUTIONS............ QLD.
ABSOLUTE STAINLESS & AL.
GLASS CONECXIONS
ACE SHEETMETAL......PORTLAND VIC
HYPERWELD
CBM RADIATORS ( WP 2000 )
SUPERIOR STAINLESS
TRUAS FAB. TECH. .........
WESS HIRE
MITCHFISH FAB.
FLYNN FABRICATION
GEORGE ANDRIC..........SCULPTOR
RITEWAY HOLDINGS............. WALLAROO
SANDVIK CONST.......ROXBY DOWNS
( WP 2000 )
WESS HIRE
J. J. RUSTON ENG. …......RENMARK
WESS HIRE
WATER INFRASTRUCTURE
WESS HIRE
DIXON PTY. LTD.
WESS HIRE
BIC INDUSTRIES
WELDTECH
VINPAK
CUSTOMERS

37. THANKYOU for your attention.
WEB SITE
www.weldcleaningsolutions.com
Email sales@wcspl.net