STUDY OF FATIGUE PROPERTIES OF ULTRA-HIGH STRENGTH STEEL

摘要

A temper-resistant, high-strength steel was investigated with refer¬ence to fatigue strength. This alloy was prepared by two different melting techniques. The first method consisted of induction melting in air using standard deoxLdation techniques. The second method involved the application of a special deoxidation practice to induction melting; silicon-free steel was deoxidized with carbon and aluminum to minimize the presence of silicate inclusions. These alloys were tested in fatigue using the Prot accelerated method. The results of the samples melted with standard practice indicated that fatigue strength is improved slightly by tempering at elevated temper¬ature. The application of a special melting process showed that a very sig¬nificant increase in the Prot fracture stress to ultimate tensile strength ratio (E /UTS) can be obtained by eliminating the presence of silicon and deoxidizing with carbon and aluminum.