Study of Microstructure and Mechanical Property Degradation of SA210 A1 Boiler Tube

The comprehension of the microstructure change and mechanical property degradation are of particular importance for assessing the integrity of aging boiler tubes.This paper describes the investigation of microstructure evolution and mechanical property degradation of SA210 A1 steel used in an actual boiler condition. The investigation deals with visual inspection, chemical composition analysis, micrograph study using Energy Dispersive Spectroscopy-Scanning Electron Microscopy (EDS-SEM), tensile test and hardness test. The result showed that the prolonged operating period in the high temperature condition resulted in the reduction of the mechanical properties of the SA 210 A1 steel tube. The study also indicated the presence of the onset of the pearlite disintegration and coagulation, resulted from the microstructure degradation of the aged steel tube after the elevated temperature service in a boiler

PENGARUH KOMPOSISI LAPISAN NI-CR PADA BAJA ASME SA 210 C TERHADAP LAJU EROSI SUHU TINGGI

The purpose of this study was to determine the high temperature erosion rate of the NiCr coating on ASME SA 210 C steel using the combustion oxy fuel thermal spray method. In Circulating Fluidized Bed (CFB) boiler, there is circulation of fly ash, silica sand and air in a high temperature environment which causes erosion. High temperature erosion can be minimized by using Ni-Cr alloy coating sing the combustion oxy fuel thermal spray method. NiCr alloy is proved a able to provider a metal alloy layer composition that can withstand temperatures of 600°C with a fly ash impact speed of 200m/s. The metal alloy compositions that have been studied are NiCr, NiCrCo, NiCrWc, NiCrWcCo, and NiCrCoMo. The results of this study indicates that metal alloys are generally atteche to the substrate and withstand at a high temperatures (600°C). The highest hardness provide by NiCrWcCo alloy which is 177.46 HV. The lowest hardness is found in the composition of the NiCrCo alloy (161.71 HV). The lowest high temperature erosion rate was found in the NiCrWcCo alloy, which was -0.00481 gram/minute. This low erosion rate because the NiCrWcCo alloy produces a good weeting effect for metal alloys and has a high hardness value

Evolution of Microstructure and Wear Resistance of Carburized Low Carbon Steel

The main aims of this present work were to investigate the microstructure and wear resistance of AISI 1020 during the pack carburization. The samples were prepared in a rectangular shape with a dimension of 5 mm X 25 mm X 2 mm for microstructure and hardness studies. Another set of samples with a dimension of 4.0 cm x 2.5 cm x 0.5 cm was prepared for the wear resistance performance. Both sets of samples were packed in the steel container which was tightly sealed. The carburizing atmosphere in the container was prepared by using mixtures of powdered charcoal and tamarind catalysts. The carburizing temperature of 950 °C with a fixed carburizing time of 2 hours was controlled for the pack carburizing treatment. The results exhibited that in the fresh condition, AISI 1020 mostly contained ferrite. Nevertheless, after carburization, quenching, and tempering process were carried out, the microstructures of the samples were changed from ferrite to pearlite and then martensite. An increase in the carbon content after carburization plays a major role in the evolution of the high hardness layers which subsequently enhanced the hardness and the wear resistance performance of AISI1020 after quenching and tempering

Advanced Industrial Materials (AIM) Program: Annual progress report FY 1995

In many ways, the Advanced Industrial Materials (AIM) Program underwent a major transformation in Fiscal Year 1995 and these changes have continued to the present. When the Program was established in 1990 as the Advanced Industrial Concepts (AIC) Materials Program, the mission was to conduct applied research and development to bring materials and processing technologies from the knowledge derived from basic research to the maturity required for the end use sectors for commercialization. In 1995, the Office of Industrial Technologies (OIT) made radical changes in structure and procedures. All technology development was directed toward the seven ``Vision Industries`` that use about 80% of industrial energy and generated about 90% of industrial wastes. The mission of AIM has, therefore, changed to ``Support development and commercialization of new or improved materials to improve productivity, product quality, and energy efficiency in the major process industries.`` Though AIM remains essentially a National Laboratory Program, it is essential that each project have industrial partners, including suppliers to, and customers of, the seven industries. Now, well into FY 1996, the transition is nearly complete and the AIM Program remains reasonably healthy and productive, thanks to the superb investigators and Laboratory Program Managers. This Annual Report for FY 1995 contains the technical details of some very remarkable work by the best materials scientists and engineers in the world. Areas covered here are: advanced metals and composites; advanced ceramics and composites; polymers and biobased materials; and new materials and processes