Electrochemical Studies of WC-Flyash HVOF Coating Interface on SA209-T1 Steel under 3.5 NaCl Solution

In this present research, the coatings of SA209-T1 using high velocity oxygen fuel were employed for the application of boiler tubes. Due to the adaptation of corrosion easy in boiler material, the research of those properties is significant because of its criticality and functionality during the service time. A right coating was found and applied on the SA209-T1 surface against corrosive environments. Good corrosion resistance is achieved by WC-flyash coatings applied on SA209-T1 substrate. The 90% WC-10% flyash coatings were found to be more protective followed by SA209-T1 steel. WC-flyash covering was tracked down so that the covering is compelling to secure the SA209-T1 steel substrate. It is reasoned that the arrangement of NiO, Cr2O3, CoO, and NiCr2O4 could add to the advancement of consumption opposition in coatings. The steel of uncoated endured erosion as extraordinary stripping and spalling of the scale, which could be because of the development of Fe2O3 oxide scale unprotectively. This paper reveals the performance, applications, and development of 90wt.% WC and 10wt.% fly ash through HVOF coating in SA209-T1 for electrochemical corrosion studies at room temperature.

Effect of Micro-Segregation on Impact Toughness of 2.25Cr-1Mo Steel after Post Weld Heat Treatment

2.25Cr-1Mo steel with high strength at high temperatures and good hydrogen resistance is widely used for power generation boiler material in high temperature and pressure use environments. Following the test evaluation of the ASME Boiler and Pressure Vessel Code, specimens from the base metal of a boiler pipe were found to have impact toughness values of 285 and 21 ft-lb, which are drastically different values. The analysis of the fracture surface of the 21 ft-lb test specimen revealed MnS inclusions, and it was found that cracks initiated at the inclusions. Observation of the cross-section of the crack propagation front revealed that cracks propagated along the ferrite regions and precipitate voids. Inclusions were also found in the 285 ft-lb impact specimen; however, the volume fraction of the inclusions was significantly less than that of the 21 ft-lb specimen. It was also found that the ferrite and carbide content of the 285 ft-lb specimen was less than 21 ft-lb specimen. The reason that the inclusions, ferrite, and carbide content differed in the two adjacent impact test specimens was analyzed. The effects of micro-segregation, such as MnS inclusions on ferrite and carbide, were compared and analyzed.

Graphene's Application to Boiler's Fabrication and Design

Problem Statement: Boilers have enormous applications and usefulness in power generation. It is to be reckoned as an all time employee in power generation sector and it is a device to create steam by applying heat energy to the water. It can also be used as steam generators. The pressure vessel of a boiler usually made of steel (or alloy steel), or historically of wrought iron is extremely exposed to the corrosion and embrittlement. This causes additional problems like boiler breakdown which can cost thousands of dollars in equipment repairs, as well as hundreds of thousands of dollars for additional property damage and business income losses. Despite numerous methods to minimize this problem the world hasn’t come up with a concrete solution. Still today boiler accidents cause heavy economic and personal losses. Can we ever come up with a solution to almost nullify this problem with all the advancements in Material Sciences in recent years?Proposed Solution: We aim at coating the inner side of boiler with deposition of membrane of oxide of recently discovered super-material graphene. Researchers found that a multilayer of graphene dioxide when stacked up together act as perfect molecular sieves when immersed in water, blocking all molecules or ions with a hydrated size larger than 4.5 Å. Caustic Embritllement causing prime agent NaOH clearly is not contained within limits described in its molecular form. Also we found that except for water vapors it does not allow any other gas to bypass it hence we ideate that prime corrosion causing agents like dissolved O2 and C02 will not interact with boiler material and hence will significantly remove boiler corrosion.Conclusion: Incorporating this hypotheses we tend to believe that prime boiler enemies will exert their least presence on boiler's functioning and its life. Its working life will be enhanced by several times. We believe that use of the latest advancement witha rather primitive subject of boilers will create a wave within boiler industries and help them to enhance boilers working and increase its life. Also it will eliminate the causticity of boiler water.