Plastic deformation and strain-induced martensite (SIM, α 1 ) transformation in metastable austenitic AISI 304 stainless steel were investigated through room temperature tensile tests at strain rates ranging from 2ˆ10´6 to 2ˆ10´2/s. The amount of SIM was measured on the fractured tensile specimens using a feritscope and magnetic force microscope. Elongation to fracture, tensile strength, hardness, and the amount of SIM increased with decreasing the strain rate. The strain-rate dependence of RT tensile properties was observed to be related to the amount of SIM. Specifically, SIM formed during tensile tests was beneficial in increasing the elongation to fracture, hardness, and tensile strength. Hydrogen suppressed the SIM formation, leading to hydrogen softening and localized brittle fracture.

Here we report the design of a ceramic phosphor plate made up of different functional materials, such as SiO2 and MgO, and Lu3Al5O12:Ce3+ (LuAG:Ce) for the fabrication of remote phosphors in high-power LED applications.

Room temperature tensile tests have been conducted at different strain rates ranging from 2 9 10 À6 to 1 9 10 À2 /s on hydrogen-free and hydrogen-charged 304 stainless steel (SS). Using a ferritescope and neutron diffraction, the amount of strain-induced martensite (SIM) has been in situ measured at the center region of the gage section of the tensile specimens or ex situ measured on the fractured tensile specimens. The ductility, tensile stress, hardness, and the amount of SIM increase with decreasing strain rate in hydrogen-free 304 SS and decrease in hydrogen-charged one. Specifically, SIM that forms during tensile tests is beneficial in increasing the ductility, strain hardening, and tensile stress of 304 SS, irrespective of the presence of hydrogen. A correlation of the tensile properties of hydrogen-free and hydrogen-charged 304 SS and the amount of SIM shows that hydrogen suppresses the formation of SIM in hydrogen-charged 304 SS, leading to a ductility loss and localized brittle fracture. Consequently, we demonstrate that hydrogen embrittlement of 304 SS is related to hydrogen-suppressed formation of SIM, corresponding to the disordered phase, according to our proposition. Compelling evidence is provided by the observations of the increased lattice expansion of martensite with decreasing strain rate in hydrogen-free 304 SS and its lattice contraction in hydrogen-charged one.