Hot Corrosion Studies of HVOF-Sprayed Cr3C2-NiCr Coating on 310S Stainless Steel in an Actual Environment of a Coal Fired Boiler

The present investigation is an attempt to evaluate the hot corrosion behaviour of high velocity-oxy fuel (HVOF) sprayed Cr3C2-25 % NiCr coating on 310S stainless steel in an actual industrial environment of a coal fired boiler. The cyclic studies were performed in the super heater zone of a coal-fired boiler where the temperature was around 700±100C. Experiments were carried out for 3 cycles each of 500 hours duration followed by 1 hour cooling in air till room temperature. X-ray diffraction (XRD) analysis and field emission scanning electron microscope (FESEM, FEI, Quanta 200F Company) with EDAX Genesis software attachment were used to analyse the oxidation-erosion products. The Cr3C2-25wt% NiCr coated specimen showed good adherence to the 310S SS substrate with negligible microspalling of the scales. The Cr3C2-25wt % NiCr coating deposited on 310S stainless steel imparted better hot corrosion resistance than the uncoated one in the given environment.

Nucleotomy Alters Mechanical Function Following Cyclic Loading and Unloaded Recovery of Human Discs

The intervertebral disc plays a critical role in supporting loads, permitting spinal motion, and dissipating energy. Unfortunately, it is also commonly degenerated, resulting in altered spinal mechanics and low back pain. Nucleotomy is a common treatment for herniated discs and is also used experimentally to simulate degeneration.[1] The procedure, which involves a posterior annular incision and removal of a portion of the nucleus pulposus (NP), has also been shown to alter disc mechanics. These changes include acute changes of decreased NP pressure, decreased disc height, and increased neutral zones.[2, 3] Cyclic studies have shown that trans-endplate nucleotomy permanently alters creep mechanical properties of sheep discs.[4] However, the effects of annular nucleotomy on the cyclic properties of human discs have not yet been studied. This work studied the mechanical effect of annular nucleotomy on human discs subjected to physiological axial cyclic loading.