Effects of nano-ceramic additives on high-temperature mechanical properties and corrosion behavior of 310S austenitic stainless steel

A novel approach to reduce Ni content for the 310S austenitic stainless steel was proposed. The nano-ceramic additive (L) was applied to 310S steel to replace part of Ni element and reduce the cost. By means of thermal simulation, X-ray diffraction, field emission scanning electron microscopy, and electron backscattered diffraction, the effects of nano-ceramic additives on high-temperature mechanical properties and corrosion behavior of the 310S steel were studied. The results indicate that the morphology and density of the (Fe, Cr)₂₃C₆ carbides are varied, which play an important role in the high-temperature mechanical properties and corrosion behavior. After adding nano-ceramic additives, the high-temperature tensile strength and yield strength are improved simultaneously, in spite of a slight decrease in the total elongation. During high-temperature corrosion process, the mass gain of all the samples is parabolic with time. The mass gain is increased in the 310S steel with nano-ceramic additive, while the substrate thickness is significantly larger than 310S steel. The more stable and adherent FeCr₂O₄ spinel form is the reason why the high-temperature corrosion resistance was increased. The (Fe, Cr)₂₃C₆ carbides distribution along grain boundaries is detrimental to the high-temperature corrosion resistance.