INOMAK AISI 304 STAINLESS STEEL REPORT

Knowledge and Truth should be diffused, so that better products are offered in better prices in the end of promoting aggregate social welfare.

The foodservice equipment industry and in particular the sector of commercial refrigerators and stainless steel catering products goes through a deregulation phase due to the major upstream price fluctuations of Stainless Steel. This is due to the fact that the basic constructional material of commercial refrigerators and stainless steel catering products is high-grade 300 series stainless steel (AISI 304-316) - which by the way is is INOMAK's field of expertise.

QUESTIONS

1. Why is High grade stainless steel 300 series considered to be the best among all the available choices?

2. Which other characteristics render it the "first" choice of the leading commercial refrigeration and catering equipment manufacturers?

3. Do materials that empirically resemble High grade AISI 304 exist, and yet exhibit properties that in the long-term could harm the reputation of our/your enterprise?

4. Do empirical or other ways of identification of the materials in discussion exist?

5. Are there any protection measures from the trading of inadequate materials of our enterprise and our customers?

If you can give satisfactory answers to the questions above, it probably means that you are adequately informed about the developments in the market and consequently you both comprehend INOMAK's commercial policy during last year and the benefits the cooperation with us offers you. If nevertheless, for some reason or other your information is blurred, you should continue reading through the next pages of this report in order to be informed on how to avoid the dangers that you may face.

ANSWERS

1. Why is High grade stainless steel 300 series considered to be the best among all the available choices?

The basic commercial series of stainless steel are the following three: Series 200, 300 and 400. In order for a steel alloy to be categorized as stainless steel, its chromium content must be at a minimum level of 10.5%. Chromium protects steel from corrosion, forming an oxide which creates a passive layer over the main body of steel therefore preventing the material from rusting away (in the opposite case atoms of oxygen would react with iron creating an exterior layer of rust - iron trioxide). AISI 304 High grade stainless steel with chromium content between 18%-20% provides significantly better protection than 200 series antimagnetic stainless steel with chromium content between 16%-18%. The 200 series stainless steel contains also nickel in significantly lower proportions and is far cheaper than 300 series stainless steel. Finally series 400 magnetic stainless steel is a lot cheaper too.

2. Which other characteristics render it the "number one" choice of the leading professional refrigeration and catering equipment manufacturers?

High grade stainless steel series 300 provides superior protection from corrosion of all types, most common of which is the pitting corrosion. The pitting corrosion is considered to be the most serious problem in the category of products at hand, due to the presence of water and acids in the foods (e.g. acidic sauces). A series of pictures of the most common types of corrosion is presented below in order to better illustrate the different types.

Pitting corrosion

Crevice corrosion

Stress cracking corrosion

Lintergranular corrosion

Uniform surface corrosion

Studies show, that the required grade on pitting corrosion resistance is found in the area of 400 degrees and above in the graph scale. The degree of protection that the several stainless steel series provide is depicted in the diagram below. It is obvious from the graph that neither the antimagnetic 200 series stainless steel nor the magnetic 400 series stainless steel are included in the area specified.

The additional characteristics that support the superiority of 300 series stainless steel are the following:

a) The absence of manganese that renders it suitable for extrusion .

b) The presence of nickel (in excess of 8%) that increases ductility (resistance in the plastic deformity: http://en.wikipedia.org/wiki/Stress_corrosion_cracking) and deters cracking.

c) Its exceptional finish in comparison to 200 series manganese stainless steel.

d) The fact that its waste can be completely recycled.

3. Do materials that empirically resemble High grade 300 series stainless steel (AISI 304) exist, and yet exhibit properties that in the long-term could harm the reputation of our your enterprise?

Unfortunately 200 Series stainless steel cannot be visually or empirically distinguished , sometimes even by the expert eye. The 400 series magnetic stainless steel can be easily identified by the simple touch of a magnet on the surface of the material. It is rather obvious, that the above materials are neither reliable nor suggested for the heavy duty use in professional kitchens. It is certain that professionals, who equip restaurant, hotel and hospital kitchens with refrigeration or neutral products made of these materials, seriously risk the fame and the long run prosperity of their enterprises.

4. Do empirical or other ways of identification of the materials in discussion exist?

As mentioned above empirical methods to identify the 200 series stainless steel do not exist.

Nippon Steel has recently commercialized though a pen checker that detects manganese stainless steel through a simple and quite effective technique (http://www.ns-sc.co.jp/english/news/20050915.html).

There are also scientific methods that accurately identify Manganese steel which nonetheless require the use of specialised technology, such as spectroscopic control (which is mainly being done in the General Chemical laboratory of State or other public institutions).

5) Are there any protection measures from the trading of inadequate materials of our enterprise and our customers?

It is necessary that you require from your supplier to determine with precision the materials that he supplies as the great majority of stainless steel mills have established traceability routines in their production process. A positive by-product of the former is that there is no batch of stainless steel in the market that cannot be referred to a Mill certificate analytical of the composition and other properties of the material. The bureaucratic control of this certificate on the enterprise's part of the materials saves a lot of trouble.

INOMAK, acting on the principles of respect and responsibility towards its customers as well as the final users of its products, guarantees the use of stainless steel AISI 304 in every case that this is mentioned in the technical characteristics of its products. Apart from the exhaustive control of the certificates of materials we use, within the context of the ISO 9001:2000 total Quality control management system, we have invested in spectroscopic meter technology in order to check and certify all incoming metal sheets.

We should thank companies UGINE & ALZ and OUTOKUMPU that facilitated the writing of the report.