تاثير تنش اعمالي و عمليات حرارتي روي رفتار خزش در دماي محيط فولاد پراستحكام A1S04141

Effect of heat treatment and applied stress on room temperature creep behavior of AISI 4140 high strength steel

Room temperature creep behavior of AISI 4140 high strength steel has been investigated at stresses lower than yield stress. After accomplishing heat treatment and determination of mechanical properties by tension test, room temperature creep tests were performed at 0.75 yield stress, 0.85 yield stress and 0.95 yield stress and creep curves were plotted. In all conditions, Creep curves agreed well with logarithmic creep law. It is demonstrated that for similar structure, higher stresses led to increased creep strains. For Quenched & Tempered specimens, the decrease in creep strain compared with other specimens in the same stress level, has been mainly attributed to the absence of ferrite. Room temperature creep mechanism(s) has been identified.