Nippon Steel & Sumikin Stainless Steel Corporation announced that it has developed the world's first tin added low interstitial ferritic steel grades, named the "FW (forward) series". This was achieved by making use of NSSC's own seed technology that can drastically improve the corrosion resistance of ferritic stainless steel by adding a micro amount of tin. The FW series steel exhibits not only improved corrosion resistance but also increased workability.
NSSC also announced that from July it has begun marketing distributing the first FW series steel, "NSSC(R) FW1", a highly corrosion resistant, low chrome, and low interstitial ferritic stainless steel, which consists of 14% chrome but which has a corrosion resistance level equivalent to 18% chrome stainless steel grades.
NSSC FW1 has the highest level workability among ferritic steel sheets, thus it can be adopted to a wide range of applications, including those in which existing 18% Cr grades are often used. Since NSSC FW1 is an ultra fine grained steel with low alloy elements, it conserves alloy resources and is stable in cost by minimizing the effect of fluctuations of raw material prices.
Because NSSC FW1 exhibits these excellent functions and characteristics, NSSC markets it with the hope that it will become a candidate for a new general purpose grade that can substitute existing grades including two leading types of steel and Tp430, which account for more than 50% of all distributed stainless steel.
Basic technology of NSSC(R) FW1
1) NSSC FW1 uses a unique seed technology, in which the corrosion resistance is drastically improved using NSSC's low interstitial technology with micro amounts of tin. This is the world's first tin added, low interstitial ferritic steel. Both corrosion resistance and workability superior to 18% chrome were achieved by adding micro amounts of tin to a base of 14% chrome.
2) Tin exists as an oxide in a Passivation film, which consists of a chrome oxide, and also exists substantially in the most superficial layer of the base immediately below the Passivation film in the metal status. Tin is thought to enhance the stability and protection performance of the Passivation film and contributes to the regeneration capacity of the Passivation film itself.
Solutions offered by NSSC(R) FW1
NSSC(R) FW1 contains only 14% chrome; however, it exhibits a corrosion resistance exceeding 18% chrome stainless steel, while, among low interstitial ferritic steel, it also shows top level workability and surface quality including anti ridging characteristics after being processed. NSSC(R) FW1 can establish its value in various applications for kitchen tools, electrical appliances, building components, and cooking utensils, etc, which are standard applications for 18% chrome stainless steel grades.
NSSC has already received high marks from customers who tried this steel before the commencement of marketing.
NSSC is currently positioning this grade as one of its main sheet products; as NSSC(R) FW1 could become a new standard steel candidate that can be used in a wide variety of applications in the same way as the two leading steels are currently used. NSSC plans to actively expand the product's applications.
In December 2010, NSSC plans to make the further announcement of a new product with even higher corrosion resistance, the "NSSC(R) FW2", a new type of steel grade from the same series as NSSC(R) FW1, which also utilizes a micro amount of tin.