A free-machining, ferritic alloy with 13% chromium is intended for products that need magnetic characteristics because it has improved corrosion resistance and good magnetic properties. Chrome Core 13-XP alloy, from Carpenter Technologies Corp, Wyomissing, Pa., (cartech.com) can be considered for electromechanical devices where corrosion resistance must be better than that of pure iron, low-carbon steel, and silicon-iron alloys.

Typical mechanical properties for Chrome Core 13-XP alloy, as annealed for optimum magnetic properties, are: 45 ksi (310 MPa) yield strength, 70 ksi (483 MPa) ultimate tensile strength, 35% elongation in 2 in. (50mm) and 50% reduction in area.

This grade has magnetic properties equivalent to those of the company's Chrome Core 13 FM alloy, with corrosion resistance superior to that of Type 430 FR alloy. In salt spray-corrosion-testing, Chrome Core 13-XP alloy provided better resistance than the higher alloyed 18% chromium ferritic stainless steels, without the substantial decrease in saturation induction typical of the stainless steels. Applications could include a variety of devices requiring some degree of corrosion resistance, either in service or for extended shelf life without the need and expense for protective coatings.