Electroless Nickel-plated Steel versus Stainless Steel: Case Studies
This paper highlights two case studies of manufacturers that have replaced, or done studies to replace, stainless steel with electroless nickel-plated mild steel. In both cases, cost savings could be realized while maintaining or improving product quality.
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Greer, South Carolina, USA
Editor’s Note: This paper is a peer-reviewed and edited version of a presentation delivered at NASF SUR/FIN 2014 in Cleveland, Ohio on June 9, 2014. A printable PDF version is available by clicking HERE.
This paper highlights two case studies of manufacturers that have replaced, or done studies to replace, stainless steel with electroless nickel-plated mild steel. In both cases, cost savings could be realized while maintaining or improving product quality. It is the hope of this author that the information included herein will allow or inspire metal finishers and manufacturers to consider such options to save costs, boost competitiveness and increase finishing sales.
Keywords: electroless nickel-plated steel, stainless steel
Corrosion resistant steels have been in existence for well over a thousand years. One of the earliest examples is the Iron Pillar of Delhi (Fig. 1). This Hindu monument was constructed around 400 A.D. from an iron-, and interestingly enough, phosphorus alloy. Its longevity and corrosion resistance are due to the formation of a phosphate film on the surface of the metal. After 1600 years in the open air, it has barely corroded, and the phosphate film has grown by just 1/20 of a millimeter.
There are many other instances of historic corrosion resistant steels, but commercial, large production practicality has come only in the last 100 years with the development of the electric arc furnace (EAF), in which most of today’s stainless steels are produced.
Most corrosion resistant, or stainless, steels today owe their stain and corrosion resistance to high levels of chromium and nickel in the alloy. There are over 150 grades of stainless steel available on the market today. These can be classified into five groups: austenitic, martensitic, ferritic, precipitation-hardened and duplex. This study only considers the austenitic alloys 303 and 304, and the martensitic alloy 416R.
Austenitic stainless steels (200 and 300 series) are generally more corrosion resistant than the martensitic stainless alloys, but as a rule, they cannot be hardened by heat treatment. Martensitic stainless steel alloys (400 series) can be hardened by heat treatment, but usually are not as corrosion resistant as the austenitic alloys. Composition comparisons are shown in Table 1.