The Production and Properties of 180 Ksi Minimum-Yield-Strength Maraging Steels

摘要

This report describeds the production and properties of hemispheres produced from 5/8-inch-thick plate, of 1/4-, 1/2-, 1-1/4-, 1-1/2-, 1-3/4-, 2-, 3-, and 4-1/2-inch-thick plates, and of 1/16-inch-diameter welding electrodes pro duced under this contract. Plates for 5/8-inch-thick hemispheres were from a part of an 80-ton electricfurnace heat of 18Ni-8Co-2.6Mo steel. Because plates 1 inch thick and over from this heat did not meet the Charpy impact-test specifications, all plates other than the 5/8inch-thick plate were produced from 20-ton electricfurnace heats of 12Ni-5Cr-3Mo steel. Welding electrodes of both the 18Ni-8Co-2.6Mo and 12Ni-5Cr-3Mo steel compositions were produced from 300-pound vacuuminduction furnace heats. The results of tension and impact tests showed that all materials met the mechanical-property specifications. In addition, the results of supplementary studies on aging response, stress-strain characteristics in tension and compression, moduli of elasticity, coefficients of thermal expansion, transformation temperatures, and grain size and microstructure of the two steels are reported. (Author)