Effect of austenite stability on fatigue performance of TRIP 700 steel

The role of austenite stability on fatigue performance of low-alloy TRIP steel 700 has been experimentally investigated. Heat treatment process was used to produce varying microstructures, characterized by different initial retained austenite volume fraction and austenite stability. Fatigue tests were carried out to determine the S-N fatigue curve of the materials. The austenite stability was measured with implementation of the Mσ s temperature detemination method. The effect of austenite stability on fatigue behavior was assessed by measurements of austenite volume fraction before and after fatigue testing. The experimental results showed that austenite stability impacts fatigue performance of TRIP steel in the high cycle regime

On the effect of austenite stability on high cycle fatigue of TRIP 700 steel

The high cycle fatigue behavior and the role of austenite stability on fatigue performance of low-alloy TRIP steel 700 have been experimentally investigated. The material was subjected to heat treatment in order to produce microstructures with different initial retained austenite volume fraction and austenite stability. High cycle fatigue tests were carried out to determine the S-N fatigue curve while austenite stability was measured by implementing a special technique for determination of M-s(sigma) temperature. The effect of austenite stability on fatigue behavior was assessed by measurements of volume fraction austenite before and after fatigue testing. The fatigue results indicated that austenite stability influences fatigue performance of TRIP steel in the high cycle regime, especially at high cyclic stresses. (C) 2013 Elsevier B.V. All rights reserved

Electrical stimulation therapies for spinal fusions: current concepts

Electrical stimulation therapies have been used for more than 30 years to enhance spinal fusions. Although their positive effects on spinal fusions have been widely reported, the mechanisms of action of the technologies were only recently identified. Three types of technologies are available clinically: direct current, capacitive coupling, and inductive coupling. The latter is the basis of pulsed electromagnetic fields and combined magnetic fields. This review summarizes the current concepts on the mechanisms of action, animal and clinical studies, and cost justification for the use of electrical stimulation for spinal fusions. Scientific studies support the validity of electrical stimulation treatments. The mechanisms of action of each of the three electrical stimulation therapies are different. New data demonstrates that the upregulation of several growth factors may be responsible for the clinical success seen with the use of such technologies