This paper describes the results of four thermochemical surface treatments of austenitic stainles... more This paper describes the results of four thermochemical surface treatments of austenitic stainless steels carried out at 450oC in a fluidised bed furnace and they are nitriding, carburizing and the newly developed hybrid process involving the simultaneous and sequential incorporation of nitrogen and carbon to form a dual layer structure in order to achieve much enhanced surface hardness and wear resistance without compromising the corrosion resistance of the steel. In all these treatments there formed alloyed layers with a common feature of being precipitation-free and supersaturated with nitrogen, or carbon or both in the austenite lattice which is known as S Phase or expanded austenite. However the layer thickness was not uniform in any of these treatments and an effective layer was produced after 8h treatment duration. The nitriding treatment produced thicker and harder layer compared to other treatments; the maximum hardness was over 1500 Hv for nitriding and the minimum hardness of 500 Hv for carburizing treatment. The nitriding treatment sample gave high wear resistance which corresponded to high hardness values.
Stainless steel is widely used where corrosion resistance is importance. Stainless steel has its ... more Stainless steel is widely used where corrosion resistance is importance. Stainless steel has its origin excellent corrosion resistance due to the nature of presence Cr as alloying element to form stable passive layer that protects the steel. Due to its inherent austenitic structure, this material has relatively low hardness as well as poor wear resistance which hinders a wider applicability of the material and may cause problems in existing applications. The gaseous thermochemical treatments to improve surface properties of material are typically carried out in carbon and/or nitrogen bearing gases and usually associated with temperature above 500 °C.
This chapter measures surface mechanical properties of hybrid-treated layers at low temperature u... more This chapter measures surface mechanical properties of hybrid-treated layers at low temperature using nanoindentation method. The tools to characterize the treated layers including its roughness were performed by FESEM (Field Emission Scanning Electron Microscope) and USPM (Universal Scanning Probe Microscope). These hybrid-treated samples have shown an increase in hardness and elastic modulus compared to the untreated sample. Moreover, all treated samples have improvement on E/H ratio which shows a decrement to plastic deformation and degrade the disparity of properties, while maintaining the elastic range of deformation.
The impact test is a test to measure the material's durability against shock loads. The impac... more The impact test is a test to measure the material's durability against shock loads. The impact test simulates the operating conditions of that material often found where the load does not always occur slowly but rather came suddenly. The impact test instrument to be designed in this study is a Drop Weight Tester (DWT) tool. This impact test apparatus utilizes mass objects and gravitational forces. Design of Drop Weight Tester (DWT) tool, design the design refers to the ASTM D-5420-04 standard. In this study the design the impact test apparatus analy z ed the strength of the connection as well as the construction deflection for ensure design results can be made. On testing Drop Weight Tester, objects the test is given a shock load with certain criteria such as altitude, load, dimension punch component striker as well as specimen thickness. At the same time it is done observation and data collection of the energy absorbed during the test. Specimen used is SPCC and Zincalume materi...
Austenitic stainless steels have been treated thermochemically in gaseous environments of ammonia... more Austenitic stainless steels have been treated thermochemically in gaseous environments of ammonia, methane or a mixture of ammonia-methane in fluidised bed furnace at temperature 450 O C for 8 h time period. The purpose of this investigation is to enhance the mechanical properties, especially the hardness and wear resistance of austenitic stainless steel without compromising its corrosion resistance. In general the thermochemical processes are carried out in such conditions so that formation of nitride and carbide precipitates is avoided because they reduce the corrosion resistance of the alloyed layers. In the present investigation, it was possible to produce hardened case layer by changing the process variables of the techniques. Analysis of the treated specimens using Optical microscope, Microhardness tester, Linear Taber Abraser, Field Emission Scanning Electron Microscope and X-ray diffraction show that low temperature treatments at 8 h can produced a hard layer without precipi...
... Surf. Coat. Technol., 2008, 202, p 40694075 12. XY Li, J. Buhagiar, and H. Dong, Characteris... more ... Surf. Coat. Technol., 2008, 202, p 40694075 12. XY Li, J. Buhagiar, and H. Dong, Characterisation of Dual S Phase Layer on Plasma Carbonitrided Biomedical Austenitic Stainless Steels, Surf. Eng., 2010, 26, p 6773 13. JC ...
Alhamdulillah, the book Recent Trends in Nanotechnology and Materials Science Engineering Materia... more Alhamdulillah, the book Recent Trends in Nanotechnology and Materials Science Engineering Materials 2014, pp 93-103 has been released online by Springerlink
Stainless steel is widely used where corrosion resistance is importance. Stainless steel has its ... more Stainless steel is widely used where corrosion resistance is importance. Stainless steel has its origin excellent corrosion resistance due to the nature of presence Cr as alloying element to form stable passive layer that protects the steel. Due to its inherent austenitic structure, this material has relatively low hardness as well as poor wear resistance which hinders a wider applicability of the material and may cause problems in existing applications. The gaseous thermochemical treatments to improve surface properties of material are typically carried out in carbon and/or nitrogen bearing gases and usually associated with temperature above 500 oC.
This paper describes the results of four thermochemical surface treatments of austenitic stainles... more This paper describes the results of four thermochemical surface treatments of austenitic stainless steels carried out at 450oC in a fluidised bed furnace and they are nitriding, carburizing and the newly developed hybrid process involving the simultaneous and sequential incorporation of nitrogen and carbon to form a dual layer structure in order to achieve much enhanced surface hardness and wear resistance without compromising the corrosion resistance of the steel. In all these treatments there formed alloyed layers with a common feature of being precipitation-free and supersaturated with nitrogen, or carbon or both in the austenite lattice which is known as S Phase or expanded austenite. However the layer thickness was not uniform in any of these treatments and an effective layer was produced after 8h treatment duration. The nitriding treatment produced thicker and harder layer compared to other treatments; the maximum hardness was over 1500 Hv for nitriding and the minimum hardness of 500 Hv for carburizing treatment. The nitriding treatment sample gave high wear resistance which corresponded to high hardness values.
Stainless steel is widely used where corrosion resistance is importance. Stainless steel has its ... more Stainless steel is widely used where corrosion resistance is importance. Stainless steel has its origin excellent corrosion resistance due to the nature of presence Cr as alloying element to form stable passive layer that protects the steel. Due to its inherent austenitic structure, this material has relatively low hardness as well as poor wear resistance which hinders a wider applicability of the material and may cause problems in existing applications. The gaseous thermochemical treatments to improve surface properties of material are typically carried out in carbon and/or nitrogen bearing gases and usually associated with temperature above 500 °C.
This chapter measures surface mechanical properties of hybrid-treated layers at low temperature u... more This chapter measures surface mechanical properties of hybrid-treated layers at low temperature using nanoindentation method. The tools to characterize the treated layers including its roughness were performed by FESEM (Field Emission Scanning Electron Microscope) and USPM (Universal Scanning Probe Microscope). These hybrid-treated samples have shown an increase in hardness and elastic modulus compared to the untreated sample. Moreover, all treated samples have improvement on E/H ratio which shows a decrement to plastic deformation and degrade the disparity of properties, while maintaining the elastic range of deformation.
The impact test is a test to measure the material's durability against shock loads. The impac... more The impact test is a test to measure the material's durability against shock loads. The impact test simulates the operating conditions of that material often found where the load does not always occur slowly but rather came suddenly. The impact test instrument to be designed in this study is a Drop Weight Tester (DWT) tool. This impact test apparatus utilizes mass objects and gravitational forces. Design of Drop Weight Tester (DWT) tool, design the design refers to the ASTM D-5420-04 standard. In this study the design the impact test apparatus analy z ed the strength of the connection as well as the construction deflection for ensure design results can be made. On testing Drop Weight Tester, objects the test is given a shock load with certain criteria such as altitude, load, dimension punch component striker as well as specimen thickness. At the same time it is done observation and data collection of the energy absorbed during the test. Specimen used is SPCC and Zincalume materi...
Austenitic stainless steels have been treated thermochemically in gaseous environments of ammonia... more Austenitic stainless steels have been treated thermochemically in gaseous environments of ammonia, methane or a mixture of ammonia-methane in fluidised bed furnace at temperature 450 O C for 8 h time period. The purpose of this investigation is to enhance the mechanical properties, especially the hardness and wear resistance of austenitic stainless steel without compromising its corrosion resistance. In general the thermochemical processes are carried out in such conditions so that formation of nitride and carbide precipitates is avoided because they reduce the corrosion resistance of the alloyed layers. In the present investigation, it was possible to produce hardened case layer by changing the process variables of the techniques. Analysis of the treated specimens using Optical microscope, Microhardness tester, Linear Taber Abraser, Field Emission Scanning Electron Microscope and X-ray diffraction show that low temperature treatments at 8 h can produced a hard layer without precipi...
... Surf. Coat. Technol., 2008, 202, p 40694075 12. XY Li, J. Buhagiar, and H. Dong, Characteris... more ... Surf. Coat. Technol., 2008, 202, p 40694075 12. XY Li, J. Buhagiar, and H. Dong, Characterisation of Dual S Phase Layer on Plasma Carbonitrided Biomedical Austenitic Stainless Steels, Surf. Eng., 2010, 26, p 6773 13. JC ...
Alhamdulillah, the book Recent Trends in Nanotechnology and Materials Science Engineering Materia... more Alhamdulillah, the book Recent Trends in Nanotechnology and Materials Science Engineering Materials 2014, pp 93-103 has been released online by Springerlink
Stainless steel is widely used where corrosion resistance is importance. Stainless steel has its ... more Stainless steel is widely used where corrosion resistance is importance. Stainless steel has its origin excellent corrosion resistance due to the nature of presence Cr as alloying element to form stable passive layer that protects the steel. Due to its inherent austenitic structure, this material has relatively low hardness as well as poor wear resistance which hinders a wider applicability of the material and may cause problems in existing applications. The gaseous thermochemical treatments to improve surface properties of material are typically carried out in carbon and/or nitrogen bearing gases and usually associated with temperature above 500 oC.
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