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This study sets out to investigate the effect of austenitising conditions on the microstructure a... more This study sets out to investigate the effect of austenitising conditions on the microstructure and impact properties of an austempered ductile iron containing Copper and Nickel and having an initially fully pearlitic structure. Un-notched Izod impact test specimens were solution treated in the range 850-1000 oc for durations between 15 and 360 min. and then austempered at 360 oc for 180min. It was shown that increasing the austenitising temperature increases the amount of carbon taken in solution by the original austenite. This reduces the driving force controlling the transformation of the austenite to the ausferrite product, ferrite and austenite. As a result, the retained austenite volume in the final microstructure increases but simultaneously its stability falls. This places an upper limit on the austenitising temperature and the amount of retained austenite permissible. On the other hand, for optimum properties, the austenitising temperature and time must be high and long enough respectively to ensure complete austenitisation. It was also shown that generally, in irons with an initially pearlitic structure, the impact properties increase steadily to a maximum value as the austenitising time increases to about 180 min. and remain constant as the soaking period extends further. Optimum properties are obtained following austenitising between 850 and 900 oc for durations of 120 to 180 min. and correspond to heat treatment cycles which saturate the initial austenite with carbon.

International Journal of Materials Technology and Innovation

Heat Affected Zone (HAZ) is the area where one or more changes from the starting state to the sol... more Heat Affected Zone (HAZ) is the area where one or more changes from the starting state to the solid state engaged in heating have occurred as a result of the welding heat cycle. In this study, we attempted to weld Austempered Ductile Iron (ADI) of initial alloys ferritic matrix using Shielded Metal Arc Welding (SMAW) with E6013 electrode. A total of six alloys of ADI were austempered at 360 °C for 180 minutes after being austenitized at 900 °C for 15, 30, 60, 120, 180, and 360 minutes. The microstructures of the weld joint were characterized by using Optical Microscope OM, and image-processing technique. The microstructure of partial fusion zone (PFZ) has nodular graphite, pearlite, and a little of martensite; austenite transformation zone (ATZ) consists of nodular graphite plus pearlite. Only a part of austenitic-ausferitic matrix can transform to austenite at the repeated transformation zone (RTZ). No obvious change in the microstructure at the base metal zone (BMZ).

Heat Affected Zone (HAZ) is the area where one or more changes from the starting state to the sol... more Heat Affected Zone (HAZ) is the area where one or more changes from the starting state to the solid state engaged in heating have occurred as a result of the welding heat cycle. In this study, we attempted to weld Austempered Ductile Iron (ADI) of the initial alloy ferritic matrix using Shielded Metal Arc Welding (SMAW) with an E6013 electrode. A total of six alloys of ADI were austempered at 360 °C for 180 minutes after being austenitized at 900 °C for 15, 30, 60, 120, 180, and 360 minutes. An optical Microscope (OM) and an image-processing technique characterized the weld joint's microstructures. The microstructure of the partial fusion zone (PFZ) has nodular graphite, pearlite, and a small fraction of martensite; the austenite transformation zone (ATZ) consists of nodular graphite plus pearlite. Only a part of the austenitic-ausferritic matrix can transform to austenite at the repeated transformation zone (RTZ). No obvious change in the microstructure at the base metal zone (BMZ).

Heat Affected Zone (HAZ) is the area where one or more changes from the starting state to the sol... more Heat Affected Zone (HAZ) is the area where one or more changes from the starting state to the solid state engaged in heating have occurred as a result of the welding heat cycle. In this study, we attempted to weld Austempered Ductile Iron (ADI) of the initial alloy ferritic matrix using Shielded Metal Arc Welding (SMAW) with an E6013 electrode. A total of six alloys of ADI were austempered at 360 °C for 180 minutes after being austenitized at 900 °C for 15, 30, 60, 120, 180, and 360 minutes. An optical Microscope (OM) and an image-processing technique characterized the weld joint's microstructures. The microstructure of the partial fusion zone (PFZ) has nodular graphite, pearlite, and a small fraction of martensite; the austenite transformation zone (ATZ) consists of nodular graphite plus pearlite. Only a part of the austenitic-ausferritic matrix can transform to austenite at the repeated transformation zone (RTZ). No obvious change in the microstructure at the base metal zone (BMZ).

ISTJ, 2023

Austempered ductile iron (ADI) has complex microstructure containing a multiphase matrix called "... more Austempered ductile iron (ADI) has complex microstructure containing a multiphase matrix called "austferite". The corrosion resistance of ADI is related to its microstructure which is determined by heat treatment parameters (austempering temperature, austempering time, austenitizing temperature and austenitizingtime). In this work, the electrochemical behavior and corrosion resistance of ADI have been investigated by electrochemical and nonelectrochemical tests in chloride media. Particular attention has been paid to the influence of austenitization time (30,60,120,180,360 and 390) on the microstructure and their influence on ADI corrosion behavior. It has been shown that ADI austenitization at 850⁰C for different times and austempered at 360 0 C for three hours has generally ausferritic microstructure. Retained austenite ranges between 20% to 40%. Hardness increasesd with increasing austenitization time. Electrochemical and non-electrochemical testing in chloride solution showed general corrosion and pitting corrosion was observed in one sample in the electrochemical test.

Austempered ductile iron (ADI) has complex microstructure containing a multiphase matrix called "... more Austempered ductile iron (ADI) has complex microstructure containing a multiphase matrix called "austferite". The corrosion resistance of ADI is related to its microstructure which is determined by heat treatment parameters (austempering temperature, austempering time, austenitizing temperature and austenitizingtime). In this work, the electrochemical behavior and corrosion resistance of ADI have been investigated by electrochemical and nonelectrochemical tests in chloride media. Particular attention has been paid to the influence of austenitization time (30,60,120,180,360 and 390) on the microstructure and their influence on ADI corrosion behavior. It has been shown that ADI austenitization at 850⁰C for different times and austempered at 360 0 C for three hours has generally ausferritic microstructure. Retained austenite ranges between 20% to 40%. Hardness increasesd with increasing austenitization time. Electrochemical and non-electrochemical testing in chloride solution showed general corrosion and pitting corrosion was observed in one sample in the electrochemical test.

International Journal of Cast Metals Research, 1997

Article history: Received 28 August 2015 Accepted 15 September 2015 Available online 15 October 2015

Erosion tests showed significant reduction in the erosion rate after laser treatment at all impin... more Erosion tests showed significant reduction in the erosion rate after laser treatment at all impinging angles. Erosion resistance is improved depending on the impingement angle, (weight losses in grams at 90° > weight losses in grams at 60° > weight losses in grams at 30°). Increasing the impingement angle increases the erosion rate for both untreated and laser treated samples. The erosion mechanism was studied by SEM observation of the fracture surface. In the untreated samples the erosion was mainly by sever plastic deformation , micro-ploughing and micro-cutting while in laser treated samples ,it was by localized strain at the over lapped regions which leads to crack formation that eventually leads to fracture . This improvement in erosion resistance was attributed to the fine and homogenous structure, high hardness and the elimination of graphite nodules which were the source of notches.

Infrared thermography techniques have been used for some time in a number of engineering applicat... more Infrared thermography techniques have been used for some time in a number of engineering applications but only recently has the method be en applied for fatigue measurments of materials. This new methodology presents many advantages as apposed to the conventional Wohler method. Compared to tr aditional method this technigue enables the determination of fatigue limit in a s hort period of time, a small number of test specimens are required, NDT techniqe. In Aus tempered Ductile Iron (ADI) this leads to saving in material, mahcining, heat tr eating and testing costs. Variation of fatigue properties with austenitising time a nd tempertaure of a ductile cast iron containing copper and nickel was investigated. In gen eral samples heat treated at 850,900,950, and 1000 ℃ for 15 to 360 min have fatigue strength values which increases as the soaking period increases and fall w ith further holding in the bath. This paper shows that infrared termographa can be use to determine the fatigue prop...

The present work investigates the effect of laser surface hardening on the erosion resistance of ... more The present work investigates the effect of laser surface hardening on the erosion resistance of alloyed austempered ductile iron contain 1.5% copper and 1.5% nickel austenitized for different austenitising times.Continuous wave of CO 2 laser was used to heat by overlapping technique. The laser processing parameters used were; 1000 w, laser power, 1000 mm\min. Scanning speed and 40 L\min. Argon flow rate. After laser treatments erosion tests were carried out on the untreated and laser treated samples surfaces. The erodent particles used were pressurized silica +300 to 500 flows at speed of 50 m\sec. The erosion tests were performed at different angles 30°, 60° and 90°. Erosion tests showed significant reduction in the erosion rate after laser treatment at all impinging angles. Erosion resistance is improved depending on the impingement angle, (weight losses ingrams at 90° > weight losses in grams at 60° > weight losses ingrams at 30°). Increasing the impingement angle increase...

Erosion tests showed significant reduction in the erosion rate after laser treatment at all impin... more Erosion tests showed significant reduction in the erosion rate after laser treatment at all impinging angles. Erosion resistance is improved depending on the impingement angle, (weight losses in grams at 90° > weight losses in grams at 60° > weight losses in grams at 30°). Increasing the impingement angle increases the erosion rate for both untreated and laser treated samples. The erosion mechanism was studied by SEM observation of the fracture surface. In the untreated samples the erosion was mainly by sever plastic deformation , micro-ploughing and micro-cutting while in laser treated samples ,it was by localized strain at the over lapped regions which leads to crack formation that eventually leads to fracture . This improvement in erosion resistance was attributed to the fine and homogenous structure, high hardness and the elimination of graphite nodules which were the source of notches.

This study sets out to investigate the effect of austenitising conditions on the microstructure a... more This study sets out to investigate the effect of austenitising conditions on the microstructure and impact properties of an austempered ductile iron containing Copper and Nickel and having an initially fully pearlitic structure. Un-notched Izod impact test specimens were solution treated in the range 850-1000 oc for durations between 15 and 360 min. and then austempered at 360 oc for 180min. It was shown that increasing the austenitising temperature increases the amount of carbon taken in solution by the original austenite. This reduces the driving force controlling the transformation of the austenite to the ausferrite product, ferrite and austenite. As a result, the retained austenite volume in the final microstructure increases but simultaneously its stability falls. This places an upper limit on the austenitising temperature and the amount of retained austenite permissible. On the other hand, for optimum properties, the austenitising temperature and time must be high and long enough respectively to ensure complete austenitisation. It was also shown that generally, in irons with an initially pearlitic structure, the impact properties increase steadily to a maximum value as the austenitising time increases to about 180 min. and remain constant as the soaking period extends further. Optimum properties are obtained following austenitising between 850 and 900 oc for durations of 120 to 180 min. and correspond to heat treatment cycles which saturate the initial austenite with carbon.

International Journal of Materials Technology and Innovation

Heat Affected Zone (HAZ) is the area where one or more changes from the starting state to the sol... more Heat Affected Zone (HAZ) is the area where one or more changes from the starting state to the solid state engaged in heating have occurred as a result of the welding heat cycle. In this study, we attempted to weld Austempered Ductile Iron (ADI) of initial alloys ferritic matrix using Shielded Metal Arc Welding (SMAW) with E6013 electrode. A total of six alloys of ADI were austempered at 360 °C for 180 minutes after being austenitized at 900 °C for 15, 30, 60, 120, 180, and 360 minutes. The microstructures of the weld joint were characterized by using Optical Microscope OM, and image-processing technique. The microstructure of partial fusion zone (PFZ) has nodular graphite, pearlite, and a little of martensite; austenite transformation zone (ATZ) consists of nodular graphite plus pearlite. Only a part of austenitic-ausferitic matrix can transform to austenite at the repeated transformation zone (RTZ). No obvious change in the microstructure at the base metal zone (BMZ).

Heat Affected Zone (HAZ) is the area where one or more changes from the starting state to the sol... more Heat Affected Zone (HAZ) is the area where one or more changes from the starting state to the solid state engaged in heating have occurred as a result of the welding heat cycle. In this study, we attempted to weld Austempered Ductile Iron (ADI) of the initial alloy ferritic matrix using Shielded Metal Arc Welding (SMAW) with an E6013 electrode. A total of six alloys of ADI were austempered at 360 °C for 180 minutes after being austenitized at 900 °C for 15, 30, 60, 120, 180, and 360 minutes. An optical Microscope (OM) and an image-processing technique characterized the weld joint's microstructures. The microstructure of the partial fusion zone (PFZ) has nodular graphite, pearlite, and a small fraction of martensite; the austenite transformation zone (ATZ) consists of nodular graphite plus pearlite. Only a part of the austenitic-ausferritic matrix can transform to austenite at the repeated transformation zone (RTZ). No obvious change in the microstructure at the base metal zone (BMZ).

Heat Affected Zone (HAZ) is the area where one or more changes from the starting state to the sol... more Heat Affected Zone (HAZ) is the area where one or more changes from the starting state to the solid state engaged in heating have occurred as a result of the welding heat cycle. In this study, we attempted to weld Austempered Ductile Iron (ADI) of the initial alloy ferritic matrix using Shielded Metal Arc Welding (SMAW) with an E6013 electrode. A total of six alloys of ADI were austempered at 360 °C for 180 minutes after being austenitized at 900 °C for 15, 30, 60, 120, 180, and 360 minutes. An optical Microscope (OM) and an image-processing technique characterized the weld joint's microstructures. The microstructure of the partial fusion zone (PFZ) has nodular graphite, pearlite, and a small fraction of martensite; the austenite transformation zone (ATZ) consists of nodular graphite plus pearlite. Only a part of the austenitic-ausferritic matrix can transform to austenite at the repeated transformation zone (RTZ). No obvious change in the microstructure at the base metal zone (BMZ).

ISTJ, 2023

Austempered ductile iron (ADI) has complex microstructure containing a multiphase matrix called "... more Austempered ductile iron (ADI) has complex microstructure containing a multiphase matrix called "austferite". The corrosion resistance of ADI is related to its microstructure which is determined by heat treatment parameters (austempering temperature, austempering time, austenitizing temperature and austenitizingtime). In this work, the electrochemical behavior and corrosion resistance of ADI have been investigated by electrochemical and nonelectrochemical tests in chloride media. Particular attention has been paid to the influence of austenitization time (30,60,120,180,360 and 390) on the microstructure and their influence on ADI corrosion behavior. It has been shown that ADI austenitization at 850⁰C for different times and austempered at 360 0 C for three hours has generally ausferritic microstructure. Retained austenite ranges between 20% to 40%. Hardness increasesd with increasing austenitization time. Electrochemical and non-electrochemical testing in chloride solution showed general corrosion and pitting corrosion was observed in one sample in the electrochemical test.

Austempered ductile iron (ADI) has complex microstructure containing a multiphase matrix called "... more Austempered ductile iron (ADI) has complex microstructure containing a multiphase matrix called "austferite". The corrosion resistance of ADI is related to its microstructure which is determined by heat treatment parameters (austempering temperature, austempering time, austenitizing temperature and austenitizingtime). In this work, the electrochemical behavior and corrosion resistance of ADI have been investigated by electrochemical and nonelectrochemical tests in chloride media. Particular attention has been paid to the influence of austenitization time (30,60,120,180,360 and 390) on the microstructure and their influence on ADI corrosion behavior. It has been shown that ADI austenitization at 850⁰C for different times and austempered at 360 0 C for three hours has generally ausferritic microstructure. Retained austenite ranges between 20% to 40%. Hardness increasesd with increasing austenitization time. Electrochemical and non-electrochemical testing in chloride solution showed general corrosion and pitting corrosion was observed in one sample in the electrochemical test.

International Journal of Cast Metals Research, 1997

Article history: Received 28 August 2015 Accepted 15 September 2015 Available online 15 October 2015

Erosion tests showed significant reduction in the erosion rate after laser treatment at all impin... more Erosion tests showed significant reduction in the erosion rate after laser treatment at all impinging angles. Erosion resistance is improved depending on the impingement angle, (weight losses in grams at 90° > weight losses in grams at 60° > weight losses in grams at 30°). Increasing the impingement angle increases the erosion rate for both untreated and laser treated samples. The erosion mechanism was studied by SEM observation of the fracture surface. In the untreated samples the erosion was mainly by sever plastic deformation , micro-ploughing and micro-cutting while in laser treated samples ,it was by localized strain at the over lapped regions which leads to crack formation that eventually leads to fracture . This improvement in erosion resistance was attributed to the fine and homogenous structure, high hardness and the elimination of graphite nodules which were the source of notches.

Infrared thermography techniques have been used for some time in a number of engineering applicat... more Infrared thermography techniques have been used for some time in a number of engineering applications but only recently has the method be en applied for fatigue measurments of materials. This new methodology presents many advantages as apposed to the conventional Wohler method. Compared to tr aditional method this technigue enables the determination of fatigue limit in a s hort period of time, a small number of test specimens are required, NDT techniqe. In Aus tempered Ductile Iron (ADI) this leads to saving in material, mahcining, heat tr eating and testing costs. Variation of fatigue properties with austenitising time a nd tempertaure of a ductile cast iron containing copper and nickel was investigated. In gen eral samples heat treated at 850,900,950, and 1000 ℃ for 15 to 360 min have fatigue strength values which increases as the soaking period increases and fall w ith further holding in the bath. This paper shows that infrared termographa can be use to determine the fatigue prop...

The present work investigates the effect of laser surface hardening on the erosion resistance of ... more The present work investigates the effect of laser surface hardening on the erosion resistance of alloyed austempered ductile iron contain 1.5% copper and 1.5% nickel austenitized for different austenitising times.Continuous wave of CO 2 laser was used to heat by overlapping technique. The laser processing parameters used were; 1000 w, laser power, 1000 mm\min. Scanning speed and 40 L\min. Argon flow rate. After laser treatments erosion tests were carried out on the untreated and laser treated samples surfaces. The erodent particles used were pressurized silica +300 to 500 flows at speed of 50 m\sec. The erosion tests were performed at different angles 30°, 60° and 90°. Erosion tests showed significant reduction in the erosion rate after laser treatment at all impinging angles. Erosion resistance is improved depending on the impingement angle, (weight losses ingrams at 90° > weight losses in grams at 60° > weight losses ingrams at 30°). Increasing the impingement angle increase...

Erosion tests showed significant reduction in the erosion rate after laser treatment at all impin... more Erosion tests showed significant reduction in the erosion rate after laser treatment at all impinging angles. Erosion resistance is improved depending on the impingement angle, (weight losses in grams at 90° > weight losses in grams at 60° > weight losses in grams at 30°). Increasing the impingement angle increases the erosion rate for both untreated and laser treated samples. The erosion mechanism was studied by SEM observation of the fracture surface. In the untreated samples the erosion was mainly by sever plastic deformation , micro-ploughing and micro-cutting while in laser treated samples ,it was by localized strain at the over lapped regions which leads to crack formation that eventually leads to fracture . This improvement in erosion resistance was attributed to the fine and homogenous structure, high hardness and the elimination of graphite nodules which were the source of notches.