Higher chromium content is the key.

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Nordson Xaloy, New Castle, Pa., has developed a bimetallic barrel alloy that is said to offer enhanced resistance to corrosive and abrasive wear for general-purpose extrusion and injection molding applications.

The key to the corrosion resistance of the X220 alloy is its higher chromium content relative to other barrel inlays for general-purpose use—double the chromium content of Nordson Xaloy’s own X200 inlay. The new inlay also exhibits greater hardness: 64 to 69 on the Rockwell HRC scale, as against 58 to 65 for the X200.

In acid immersion tests of sample weight loss, X220 alloy exhibited a 55% improvement over other European alloys in sulfuric acid (see graph) and a 44% improvement in hydrochloric acid.