Effect of Chromium Addition on Corrosion Resistance of Amorphous Fe-B-C and Fe-B-Si Alloys

Change in the corrosion resistance of amorphous Fe-B-C and Fe-B-Si alloys without phosphorus due to the addition of chromium has been investigated. In contrast to the amorphous Fe-Cr-P-C alloys, the addition of chromium scarcely improves the corrosion resistance of amorphous Fe-B-C and Fe-B-Si alloys in 0.1 N H_2SO_4, while their corrosion resistance in 3% NaCl increases by the addition of chromium. The amorphous Fe-Cr-B_-C_7 and Fe-Cr-B_-Si_7 alloys containing 8 and 10 at% chromium do not exhibit the critical potential for pitting on the anodic polarization curves in 3% NaCl. It is concluded from comparison among the three sets of metalloid elements that the addition of phosphorus is most effective for improving the corrosion resistance of the amorphous iron alloys containing chromium