View Sample Alloy Digest Data Sheet (PDF)Since 1952, Alloy Digest has been the leading reference for materials property data on metals and alloys used throughout the world. Featuring graphs, charts and tables, these sheets give facts and figures on composition or characterization, physical and mechanical properties, heat treatment, and machinability.ACI Type HL is an austenitic iron-chromium-nickel alloy similar to ACI Type HK (Alloy Digest, December 1974); however, the higher chromium content of Type HL gives it greater resistance to corrosion by hot gases, particularly those containing appreciable amounts of sulfur. Because essentially equivalent high-temperature strength can be obtained with either the HL or HK grades, the improved corrosion resistance of the HL alloy makes it especially useful for severe service where excessive scaling must be avoided.