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K-TIG: A Quantum Leap for Welding

Innovation Design Set to Transform the Industry

For the past six decades, the welding process has only been tweaked and modified, but one Adelaide company has developed a new process set to save millions of dollars and forever change the way welds are performed.

Revision of AS 1528: Fluid Transfer in Stainless Steel Tube and Fittings

Connections are vital

Any visit to a dairy, beverage or food processing plant will drive home the critical importance of the connections between the tanks, mixers, driers, pumps, etc. The image above (courtesy of TFG Group) showing an image of a brewery is a typical example. These tubes and/or pipes carry the process materials, the heating or cooling or wash water, gases, and also dispose of the wastes.

Welding Dissimilar Metals

Welding the common austenitic stainless steels such as 304 and 316 to each other or themselves is routine and the easiest of fusion welding. Nevertheless, there are many situations where it is necessary to weld stainless steel to carbon steel. Two common examples are balustrade posts attached to structural steel or doubler plates connecting supports to stainless steel vessels. There are differences in physical properties such as thermal conductivity and expansion, magnetic properties, metallurgical structure and corrosion resistance, which all require attention. This article outlines the necessary procedures for satisfactory welding, including reference to standards, and explains the necessary precautions. Appendix H of AS/NZS 1554.6:2012 has a more detailed technical discussion including advice on welding carbon steel to ferritic, duplex and martensitic stainless steels.

General Corrosion Resistance

The normal state for stainless

Stainless steels resist corrosion because they have a self-repairing “passive” oxide film on the surface. As long as there is sufficient oxygen to maintain this film and provided that the level of corrosives is below the steel’s capacity of the particular material to repair itself, no corrosion occurs. If there is too high a level of (say) chlorides, pitting occurs. As an example, 316 works well in tap water (<250ppm) all over Australia, but will rapidly corrode in seawater because seawater has very high chloride levels (20,000ppm).

12% Chromium Utility Stainless Steels

BACKGROUND

Almost all of the stainless steels in use have 16% chromium or more and have nickel or other additions to make them austenitic and hence formable, tough and readily weldable. However, the formal definition of a stainless steel is that it is an iron- and carbon-based alloy with more than 10.5% chromium. Historically, the corrosion mitigation industry regarded alloys with more than 12% chromium as stainless steels mainly because those alloys did not corrode in mild environments. Because of the perceived problem of high initial price when using stainless steels, alloys that are ‘barely’ stainless (and with low nickel to boot) are more competitive with painted or galvanised carbon steel than higher alloys.

Stainless Steel and Plumbing Standards

After three years of development, the first stage of a Standard covering the grade and dimensions of stainless steel pipes and tubes suitable for water supply and drainage systems has been completed. This interim Standard will be converted to a full Australian Standard in 2009.

Grade 431

A versatile, high strength martensitic stainless steel

Martensitic stainless steels are a less well-known branch of the stainless family. Their special features – high strength and hardness – point to their main application area as shafts and fasteners for motors, pumps and valves in the food and process industries.

Weathering the Financial Storm

'Remaining Competitive and Profitable' by James Johnson, Millatec Pty Ltd

Now is the time as an owner of a small or medium enterprise to move back into the coalface and be involved in all facets of your business. As a business owner, no one spends less money, identifies opportunities to improve productivity more or reduces waste better than you.

In the current economic climate it seems especially pertinent to discuss tools that can help you remain competitive and achieve break-even or be profitable.

The four key areas are:

  1. Financials
  2. Human resources
  3. Marketing
  4. Systemisation

For stainless apprentices

Posted 23rd September 2009

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At the beginning of 2008, ASSDA was successful in its application for funding from the Federal Government for a project focused on the integration of e-learning into industry. The funding has seen ASSDA create a Workforce Development Strategy and a Flexible Learning Delivery Pathway incorporating e-learning, with plans to develop an additional e-learning module titled Practical Skills of Surface Treatment to complement the existing Gas Tungsten Arc Welding Module.

Stunning stainless

Strength and corrosion resistance vital

As wild fish stocks decline globally, the spotlight is increasingly being shone on humane stun and slaughter methods in the rapidly growing aquaculture industry. Stainless steel components fabricated by Pryde Fabrication (ASSDA Accredited) are an integral part of a Brisbane innovation that is leading the way internationally in a shift towards faster and more humane automated percussive stun methods.