Alloy offers improved corrosion resistance

Carpenter Technology Corp. has introduced a controlled-chemistry, free-machining, ferritic 13 percent chromium alloy developed for use in magnetic components that offers improved corrosion resistance.

Chrome Core® 13-XP alloy can be considered for fuel injection components and other electromechanical devices in which corrosion-resistance must be better than that of pure iron, low-carbon steel, and silicon-iron alloys.

In salt spray corrosion testing, Chrome Core 13-XP alloy provided better resistancethan the higher alloyed 18 percent chromium ferritic stainless steels, without the substantial decrease in saturation induction typically exhibited by that material, the company said.

The new alloy is the latest in Carpenter's Chrome Core series ofalloys which have been used in automotive components such as fuel injectors and ABS solenoids. It can be considered for industrial solenoid components which require magnetic properties better than those for Type 430FR alloy or Chrome Core 18-FM alloy. Alternately, it is also a candidate for applications requiring a ferritic stainless steel with improved corrosion resistance.

Typical physical/magnetic properties of the new alloy are: saturation magnetization, 1.7 Bs, Tesla; maximum permeability, 43,000; resistivity, 814 microohm millimeters, and coercivity, 111 Hc,A/m.

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 percent elongation in 2 in. (50 mm) and 50 percent reduction in area.