Y.M. Chen

Microstructure Evolution of T91 Heat-Resistant Steels after Long-Time Aging

To investigate the evolution of microstructure damage degree and the precipitated phases of heat-resistant metal in power plant under high temperature and stress environment, the high-temperature aging tests were conducted to investigate the aging behavior of T91 steel at different temperatures and stress. The optical microscopy, scanning electron microscopy, and transmission electron microscopy were used to investigate the structure and precipitated phases, the results showed that the orientation characteristics of tempered martensite was dispersed, and the grain size is obviously increased. The density of dislocation decreased with increasing temperature and stress. The important strengthening phase of M23C6 (M=Fe, Cr) was coarsened by the diffusion of main alloying elements Cr, while the smaller size MX (M=Nb,V; X=C, N) phase distributed in the grain is relatively stable in the aging.

Effect of Ion Source Current on the Microstructure and Properties of Cr-DLC Coatings Prepared by Ion Beam Assisted Arc Ion Plating

Cr-containing diamond-like carbon (Cr-DLC) nanocomposite coatings were synthesized by ion beam-assisted arc ion plating with varying hollow cathode ion source (HCIS) currents. The morphologies, com...