Oxidation characterization of M2 powders exposed under humid atmosphere for a long time

Abstract

Atomized M2 powders were stored in an atmosphere of 80% relative humidity for a long time. The oxidation characteristics of atomized alloy powders were analyzed. The results show that the oxygen content of the powders have an increasing trend with the prolongation of storage time under humid atmosphere. The oxygen content of 150-300 mesh coarse powder has a gentle change, and the oxygen content will be reduced to near the original level after drying. The oxygen content of -300 mesh fine powders has a little growth in a short time, but it increases rapidly as time goes on after one week, and increases from 415 ppm to 1098 ppm after four weeks of storage, and the oxygen content of fine powders after drying remained unchanged. Particle size has a great influence on the oxidation characteristics of powders. The smaller the particle size, the greater the oxygen content of the powder. The type of adsorption of oxygen element from coarse powder to fine powder changes from physical adsorption to chemical adsorption.