Re: Material Suitability - Sodium Hypochlorate


Posted by Gordon England on October 08, 2003 at 15:09:23:

In Reply to: Material Suitability posted by John on October 08, 2003 at 09:53:34:

: Hi Gordan,

: I've trialed a WcNi coating operating in 10% Sodium Hypochlorate 40 C. The ground finish has become very rough with a black powder residue when you wipe a cloth over it. There has been no loss in Ø. I'm a bit baffeled as an earler trial has gone extremly well. Any ideas?? One thought was that the Nickle was breaking down but i cant find any info on nickel suitability with AvCl2. Any info or sites to visit would be greatfully appreciated.

: P.s. congratulations on a good forum

Hi John

Sodium Hypochlorate or more correctly named sodium hypochlorite (chemist out there please correct me if I'm wrong!)is the main constituent of bleach.

The nickel will probably be attacked, although I think the WC will be resistant. Unfortunately, most metals are attacked. Well sealed ceramic, titanium or Hastelloy C based coatings should give better corrosion protection. Have you tried WC/10Co/4Cr? though I suspect it will be no better than WC/Ni.

Info from a MSDS:

Corrosivity to Metals:
Sodium hypochlorite solutions (20%) are corrosive to brass (aluminium, naval and silicon) bronze, carbon steel, cast iron, Hastelloy, Inconel, nickel, stainless steels (types 304/347, 316 and 400 series) and silicon copper. Concentrated sodium hypochlorite is corrosive to most metals, including aluminium, copper, brass, bronze, carbon steel, Hastelloy, Inconel, lead, Monel, nickel and stainless steel type 400 series. Sodium hypochlorite solutions are not corrosive to tantalum, titanium and zirconium. Dilute solutions are not corrosive to Hastelloy C/C-276 (10%), Incolloy (5%) and high silicon iron.

This link may be worth viewing:


http://216.239.59.104/search?q=cache:VxSi62GSA6wJ:www.odysseymanufacturing.com/bleach_information.doc+metals+resistant+to+sodium+hypochlorite&hl=en&ie=UTF-8

Hope this helps

Regards gordon


Follow Ups:


Surface Engineering Forum

Surface Engineering Message Board Archive

Surface Engineering Message Board Archive Index

www.gordonengland.co.uk







Post A Message!

Gordon England Surface Engineering ForumPlease go to the new Surface Engineering Forum as this old message board is a read only archive. Please copy and paste relevant information or link to the page if you wish to reactivate a thread on the new forum.







Gordon England Independent Thermal Spray Coating Consultant
Telephone: +44 (0)1252 405186

Email: tsc@gordonengland.co.uk

Site Links



Introducing

Nature of Thermal Spray Coatings

Surface Engineering in a Nutshell

Surface Engineering Forum

Thermal Spray Gun Repair Service

Plasma Consumable Parts

Thermal Spray Powder Supplies

Applications:

Thermal Spray Coatings on Carbon and Glass Fibre Reinforced Polymers

HVOF Coating of Paper Making Roll

Abradable Coatings

Photomicrographs

Thermal Spray Processes:

Combustion Wire Thermal Spray Process

Combustion Powder Thermal Spray Process

Arc Wire Thermal Spray Process

Plasma Thermal Spray Process

HVOF Thermal Spray Process

HVAF Thermal Spray Process

Detonation Thermal Spray Process

Plasma Flame Theory

Cold Spray Coating Process



Wear and Use of Thermal Spray Coatings

Corrosion and Use of Thermal Spray Coatings

Glossary of Thermal Spray and Surface Engineering Terms

Image Directory for Thermal Spray Coatings

Plasma Gas Flow Information

Plasma Gas Flow Correction Calculator

Contact Form

Links to other interesting sites related to thermal spray and surface engineering

Reciprocal Links

Periodic Table of the Elements

SI Units

Calculators for Conversion between Units of Measurement

Hardness Testing

Surface Engineering Message Board Archive

Surface Engineering Message Board Archive Index

Photography Gallery2

Photography Gallery3


© Copyright Gordon England