Objects of iron and steel provide some of the most intractable problems for the conservator because of the variety and complexity of their corrosion products. The metals corrode easily, being attacked by oxygen in the presence of moisture. The corrosion products are ugly and deformation of an attacked object may be severe. The action of oxygen and moisture can be further compounded by the presence of salts which can cause local electrochemical activity, accelerating pitting, and mineralization. The problem for the conservator is to remove and/or stabilize the layer of corrosion products on the object, and to provide some method to prevent further corrosion. -- AATA