CLEANING ............. .

PASSIVATING ........ .

ELECTROPOLISHING .

OF

STAINLESS STEEL

PRESENTATION EXPLAINING the

WELD POSTCLEEN SYSTEM

………. its FUNCTIONS, ADVANTAGES, and

STAINLESS STEEL

ABOUT STAINLESS STEEL

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.

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

Weld Contaminants

Metal cutting fluids.

Shared metal cutting / grinding equipment.

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 .

• 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.

• 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.

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.

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.

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.

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.

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."

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.

Electropolishing

a valuable alternative.....

To Pickling paste

( Hf + Nitric )

AND

Nitric acid for Passivating

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.

Handrail Corrosion

Darling Harbour , Sydney

Grinding marks

Embedded iron

611

Should be SMOOTH

Should be CLEAN

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

STAINLESS FUME HOOD with CARBON STEEL clamping rings.

PRE and POST CLEANING stages using the GWC SYSTEM.

LITTLE PARA FLOOD GATES PRE - CLEANING

LITTLE PARA FLOOD GATES POST CLEANING – project completed

Manufacturer of the ........

STAINLESS LIFE SOLUTIONS

YOUR

WP........ WELD POSTCLEEN THE POWER SYSTEM

Pure DC , smooth, stable system

WP SYSTEM KIT

WP 1000

WP SYSTEM KIT

WP 2000

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

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

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.

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.

WP SYSTEM KITS

WP 1000

WP 2000

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

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