Rihan Rihan - Academia.edu (original) (raw)

Papers by Rihan Rihan

Journal of Materials Engineering and Performance, Sep 3, 2015

Susceptibility of SA-543 steel, its welds (with and without stress relief treatment), and the hea... more Susceptibility of SA-543 steel, its welds (with and without stress relief treatment), and the heat-affected zone (HAZ) to stress corrosion cracking (SCC) was investigated in de-aerated and aerated boiler feed water subjected to the all-volatile treatment (AVT-BFW), and distilled water at 275°C using the slow strain rate testing (SSRT) technique. The SSRT specimens were tested at three extension rates (3.50 3 10 26 , 9.00 3 10 26 , and 7.50 3 10 25 mm/s) using a novel SCC testing rig capable of testing at high temperatures and pressures. There are no significant differences in the time-to-failure among the four tested specimens. The elongation of the specimens at the time of failure is in the range of 10-23%. The reduction of the crosssectional area of the failed specimens is large (45-77%) and the absence of any signs of intergranular propagation in fractured specimens, determined by scanning electron microscopy, indicates that the failure is due to mechanical load and not due to SCC. Dissolved oxygen does not affect the susceptibility of the specimens to SCC, which could be due to the inhibition effect of the test solution. SA-543 steel as the base metal, its welds (with and without stress relief treatment), and the HAZ are suitable for use in hot AVT-BFW and distilled water.

A new technique for rapid and cost-effective determination of stress intensity factor (K I) and f... more A new technique for rapid and cost-effective determination of stress intensity factor (K I) and fracture toughness (K IC) using small circumferential notch tensile (CNT) specimens is presented and used to determine the crack growth rate of an ex-service component. The paper highlights the scope and advantages of extending this technique for assessing the susceptibility of ferrous alloys to stress corrosion cracking (SCC). A modified CNT testing rig is designed and constructed based on an existing room temperature sustained load crack testing rig by adding facilities for testing SCC susceptibility at different temperatures. The new testing rig simplifies and speeds up the testing procedure as well as provides considerable cost advantage over the conventional fracture mechanics techniques. The paper also presents results of the SCC tests carried out on mild steel (AISI 1020) using this modified CNT rig.

This thesis was scanned from the print manuscript for digital preservation and is copyright the a... more This thesis was scanned from the print manuscript for digital preservation and is copyright the author. Researchers can access this thesis by asking their local university, institution or public library to make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.

Journal of Materials Engineering and Performance, Jun 10, 2016

Corrosion resistance (R P) of X65 steel was investigated in an oil-in-water emulsion containing H... more Corrosion resistance (R P) of X65 steel was investigated in an oil-in-water emulsion containing H 2 S and CO 2 at several oil concentrations and different flow regions using a novel emulsion flow loop. One working electrode was mounted in the flow developing region while the other one was mounted in a region where the flow is fully developed. The experimental results show that the addition of CO 2 to an H 2 S containing emulsion decreases the corrosion rate. The R P in the flow developing region is less than that in the fully developed region and it increases with increasing oil concentration. This flow loop is a promising tool for investigating the R P of engineering materials in a simulated environment similar to that encountered in the petroleum industry. Keywords CO 2 , corrosion and wear, emulsion, flow loop, H 2 S, sodium thiosulfate (Na 2 S 2 O 3), X65 steel

The paper discusses a novel technique for rapid and cost-effective determination of stress intens... more The paper discusses a novel technique for rapid and cost-effective determination of stress intensity factor (K I) and fracture toughness (K Ic) using small circumferential notch tensile (CNT) specimens, and highlights the scope and advantages of extending this for developing a fracture mechanics technique for assessing susceptibility to stress corrosion cracking (SCC). The paper presents modification of the CNT testing rig for mechanical testing into an SCC testing rig that simplifies and speeds up the testing procedure as well as provides considerable cost advantage over the conventional fracture mechanics techniques. The paper also presents results of the SCC tests carried out on a cast iron using this modified CNT setup .

Corrosion Science, Sep 1, 2006

Corrosion rates of 1020 steel in 2.75 M NaOH solution at a temperature of 160°C and velocities of... more Corrosion rates of 1020 steel in 2.75 M NaOH solution at a temperature of 160°C and velocities of 0.32 and 2.5 m/s were studied. The focus was on the eVect of the acid cleaning which was performed by using strong, inhibited sulphuric acid in between the exposures to caustic. In situ electrochemical methods were used to measure the corrosion rate such as the potentiodynamic sweep and the polarization resistance method. Also used were the weight-loss method and scanning electron microscopy (SEM). Eight electrodes/coupons were used to monitor the metal loss rate, four were placed at the low velocity section, while the other four were placed in the high velocity section of a high temperature Xow. The Wrst three coupons in each section were placed within the disturbed Xow region, while the fourth was placed in a fully developed Xow region. During the exposure of mild steel to the inhibited acid, following the Wrst caustic period, the corrosion rate increased signiWcantly to between 3 and 10 mm/y with a few electrodes experiencing as high as 50 mm/y. The second caustic period following the acidic period typically started with very high corrosion rates (20-80 mm/y). The length of this corrosion period was typically 2-3 h with a few exceptions when the high corrosion period lasted 7-10 h. Following the very high corrosion rates experienced at the beginning of the second caustic period, the corrosion rates were reduced sharply (as the corrosion potential increased) to nearly the same levels as those observed during the passive part of the Wrst caustic period.

Journal of Materials Engineering and Performance, Dec 10, 2014

Anti-corrosion Methods and Materials, Oct 28, 2014

Purpose-This paper aims to report an experimental investigation of the galvanic corrosion that oc... more Purpose-This paper aims to report an experimental investigation of the galvanic corrosion that occurs between the base metal and the welds in X52 carbon steel petroleum pipelines when exposed in carbon dioxide (CO 2)-containing saltwater at pH 4 at room temperature. The pipeline was fabricated by electric resistance welding (ERW). Design/methodology/approach-The experimental setup was a closed glass cell equipped with a silver/silver chloride (Ag/AgCl) reference electrode, two working electrodes (the weld metal and the parent steel specimens) and a gas bubbler. The corrosion potential and polarization resistance of the base metal and the weld were determined using electrochemical testing methods: potentiodynamic polarization scans and linear polarization resistance measurement. The galvanic currents of the base metal when coupled to the weld metal were measured using zero resistance ammetry. Findings-The weld metal was the anode of the couple for a very short time at the beginning of the experiment and then became the cathode until the end of the experiment. This indicates that electric resistance welded X52 steel pipe is a promising material to be operated in CO 2-containing saltwater at pH 4 and 25°C because the weld area is cathodic to the parent metal, the value of the galvanic current is very low (in the order of nanoamps) and the area of the anode (i.e. the parent metal) is significantly larger than that of the cathode (weld metal). Research limitations/implications-Further experimental research could be performed to investigate the galvanic corrosion behavior between the parent metal and the weld area of X52 carbon steel petroleum pipelines in CO 2-containing saltwater at different pH values, temperature and velocity. Practical implications-Electric resistance welded X52 steel pipe is a promising material for use with CO 2-containing saltwater environments at pH 4 and 25°C. Originality/value-The new information presented in the paper is the galvanic corrosion behavior between the parent metal and the ERW weld metal of X52 carbon steel in CO 2-containing solutions. The paper should be useful to researchers working in the field of oil industry corrosion.

Materials Science and Engineering: A, 2006

A novel fracture mechanics technique has been employed for the determination of crack growth rate... more A novel fracture mechanics technique has been employed for the determination of crack growth rate and threshold stress intensity factor (K Iscc) for stress corrosion cracking (SCC) using small circumferential notch tensile (CNT) specimens. The technique was applied successfully for testing SCC susceptibility of spheroidal graphite (SG) cast iron in 5 M NaOH at 100 and 120 • C. Crack growth rate of SG cast iron in 5 M NaOH solution at 100 and 120 • C has been determined at different stress intensity factors (K I), and the K Iscc have been determined to be 11.2 and 9 MPa m 1/2 , respectively. The surfaces of fractured specimens have been examined by scanning electron microscopy (SEM) in order to establish intergranular propagation of stress corrosion cracks. CNT testing is a simple, relatively fast and cost-advantageous approach for generating crack growth rate and K Iscc data.

Materials Science and Engineering: A, 2007

Determination of threshold stress intensity for stress corrosion cracking (K ISCC), using circumf... more Determination of threshold stress intensity for stress corrosion cracking (K ISCC), using circumferential notch tensile (CNT) specimens has been developed recently. This has also been claimed to be a novel and considerably cost-advantageous approach in comparison with the traditional methods, viz., compact tension (CT) and double cantilever beam (DCB) techniques for determination of K ISCC. However, the limited first K ISCC data, generated using CNT specimens have been queried for the lack of their comparison with the data generated by other techniques. This work presented here provides the first comparative results and validation for use of the novel CNT testing for generation of K ISCC data.

This thesis was scanned from the print manuscript for digital preservation and is copyright the a... more This thesis was scanned from the print manuscript for digital preservation and is copyright the author. Researchers can access this thesis by asking their local university, institution or public library to make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.

Journal of Materials Engineering and Performance, Sep 3, 2015

Susceptibility of SA-543 steel, its welds (with and without stress relief treatment), and the hea... more Susceptibility of SA-543 steel, its welds (with and without stress relief treatment), and the heat-affected zone (HAZ) to stress corrosion cracking (SCC) was investigated in de-aerated and aerated boiler feed water subjected to the all-volatile treatment (AVT-BFW), and distilled water at 275°C using the slow strain rate testing (SSRT) technique. The SSRT specimens were tested at three extension rates (3.50 3 10 26 , 9.00 3 10 26 , and 7.50 3 10 25 mm/s) using a novel SCC testing rig capable of testing at high temperatures and pressures. There are no significant differences in the time-to-failure among the four tested specimens. The elongation of the specimens at the time of failure is in the range of 10-23%. The reduction of the crosssectional area of the failed specimens is large (45-77%) and the absence of any signs of intergranular propagation in fractured specimens, determined by scanning electron microscopy, indicates that the failure is due to mechanical load and not due to SCC. Dissolved oxygen does not affect the susceptibility of the specimens to SCC, which could be due to the inhibition effect of the test solution. SA-543 steel as the base metal, its welds (with and without stress relief treatment), and the HAZ are suitable for use in hot AVT-BFW and distilled water.

A new technique for rapid and cost-effective determination of stress intensity factor (K I) and f... more A new technique for rapid and cost-effective determination of stress intensity factor (K I) and fracture toughness (K IC) using small circumferential notch tensile (CNT) specimens is presented and used to determine the crack growth rate of an ex-service component. The paper highlights the scope and advantages of extending this technique for assessing the susceptibility of ferrous alloys to stress corrosion cracking (SCC). A modified CNT testing rig is designed and constructed based on an existing room temperature sustained load crack testing rig by adding facilities for testing SCC susceptibility at different temperatures. The new testing rig simplifies and speeds up the testing procedure as well as provides considerable cost advantage over the conventional fracture mechanics techniques. The paper also presents results of the SCC tests carried out on mild steel (AISI 1020) using this modified CNT rig.

This thesis was scanned from the print manuscript for digital preservation and is copyright the a... more This thesis was scanned from the print manuscript for digital preservation and is copyright the author. Researchers can access this thesis by asking their local university, institution or public library to make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.

Journal of Materials Engineering and Performance, Jun 10, 2016

Corrosion resistance (R P) of X65 steel was investigated in an oil-in-water emulsion containing H... more Corrosion resistance (R P) of X65 steel was investigated in an oil-in-water emulsion containing H 2 S and CO 2 at several oil concentrations and different flow regions using a novel emulsion flow loop. One working electrode was mounted in the flow developing region while the other one was mounted in a region where the flow is fully developed. The experimental results show that the addition of CO 2 to an H 2 S containing emulsion decreases the corrosion rate. The R P in the flow developing region is less than that in the fully developed region and it increases with increasing oil concentration. This flow loop is a promising tool for investigating the R P of engineering materials in a simulated environment similar to that encountered in the petroleum industry. Keywords CO 2 , corrosion and wear, emulsion, flow loop, H 2 S, sodium thiosulfate (Na 2 S 2 O 3), X65 steel

The paper discusses a novel technique for rapid and cost-effective determination of stress intens... more The paper discusses a novel technique for rapid and cost-effective determination of stress intensity factor (K I) and fracture toughness (K Ic) using small circumferential notch tensile (CNT) specimens, and highlights the scope and advantages of extending this for developing a fracture mechanics technique for assessing susceptibility to stress corrosion cracking (SCC). The paper presents modification of the CNT testing rig for mechanical testing into an SCC testing rig that simplifies and speeds up the testing procedure as well as provides considerable cost advantage over the conventional fracture mechanics techniques. The paper also presents results of the SCC tests carried out on a cast iron using this modified CNT setup .

Corrosion Science, Sep 1, 2006

Corrosion rates of 1020 steel in 2.75 M NaOH solution at a temperature of 160°C and velocities of... more Corrosion rates of 1020 steel in 2.75 M NaOH solution at a temperature of 160°C and velocities of 0.32 and 2.5 m/s were studied. The focus was on the eVect of the acid cleaning which was performed by using strong, inhibited sulphuric acid in between the exposures to caustic. In situ electrochemical methods were used to measure the corrosion rate such as the potentiodynamic sweep and the polarization resistance method. Also used were the weight-loss method and scanning electron microscopy (SEM). Eight electrodes/coupons were used to monitor the metal loss rate, four were placed at the low velocity section, while the other four were placed in the high velocity section of a high temperature Xow. The Wrst three coupons in each section were placed within the disturbed Xow region, while the fourth was placed in a fully developed Xow region. During the exposure of mild steel to the inhibited acid, following the Wrst caustic period, the corrosion rate increased signiWcantly to between 3 and 10 mm/y with a few electrodes experiencing as high as 50 mm/y. The second caustic period following the acidic period typically started with very high corrosion rates (20-80 mm/y). The length of this corrosion period was typically 2-3 h with a few exceptions when the high corrosion period lasted 7-10 h. Following the very high corrosion rates experienced at the beginning of the second caustic period, the corrosion rates were reduced sharply (as the corrosion potential increased) to nearly the same levels as those observed during the passive part of the Wrst caustic period.

Journal of Materials Engineering and Performance, Dec 10, 2014

Anti-corrosion Methods and Materials, Oct 28, 2014

Purpose-This paper aims to report an experimental investigation of the galvanic corrosion that oc... more Purpose-This paper aims to report an experimental investigation of the galvanic corrosion that occurs between the base metal and the welds in X52 carbon steel petroleum pipelines when exposed in carbon dioxide (CO 2)-containing saltwater at pH 4 at room temperature. The pipeline was fabricated by electric resistance welding (ERW). Design/methodology/approach-The experimental setup was a closed glass cell equipped with a silver/silver chloride (Ag/AgCl) reference electrode, two working electrodes (the weld metal and the parent steel specimens) and a gas bubbler. The corrosion potential and polarization resistance of the base metal and the weld were determined using electrochemical testing methods: potentiodynamic polarization scans and linear polarization resistance measurement. The galvanic currents of the base metal when coupled to the weld metal were measured using zero resistance ammetry. Findings-The weld metal was the anode of the couple for a very short time at the beginning of the experiment and then became the cathode until the end of the experiment. This indicates that electric resistance welded X52 steel pipe is a promising material to be operated in CO 2-containing saltwater at pH 4 and 25°C because the weld area is cathodic to the parent metal, the value of the galvanic current is very low (in the order of nanoamps) and the area of the anode (i.e. the parent metal) is significantly larger than that of the cathode (weld metal). Research limitations/implications-Further experimental research could be performed to investigate the galvanic corrosion behavior between the parent metal and the weld area of X52 carbon steel petroleum pipelines in CO 2-containing saltwater at different pH values, temperature and velocity. Practical implications-Electric resistance welded X52 steel pipe is a promising material for use with CO 2-containing saltwater environments at pH 4 and 25°C. Originality/value-The new information presented in the paper is the galvanic corrosion behavior between the parent metal and the ERW weld metal of X52 carbon steel in CO 2-containing solutions. The paper should be useful to researchers working in the field of oil industry corrosion.

Materials Science and Engineering: A, 2006

A novel fracture mechanics technique has been employed for the determination of crack growth rate... more A novel fracture mechanics technique has been employed for the determination of crack growth rate and threshold stress intensity factor (K Iscc) for stress corrosion cracking (SCC) using small circumferential notch tensile (CNT) specimens. The technique was applied successfully for testing SCC susceptibility of spheroidal graphite (SG) cast iron in 5 M NaOH at 100 and 120 • C. Crack growth rate of SG cast iron in 5 M NaOH solution at 100 and 120 • C has been determined at different stress intensity factors (K I), and the K Iscc have been determined to be 11.2 and 9 MPa m 1/2 , respectively. The surfaces of fractured specimens have been examined by scanning electron microscopy (SEM) in order to establish intergranular propagation of stress corrosion cracks. CNT testing is a simple, relatively fast and cost-advantageous approach for generating crack growth rate and K Iscc data.

Materials Science and Engineering: A, 2007

Determination of threshold stress intensity for stress corrosion cracking (K ISCC), using circumf... more Determination of threshold stress intensity for stress corrosion cracking (K ISCC), using circumferential notch tensile (CNT) specimens has been developed recently. This has also been claimed to be a novel and considerably cost-advantageous approach in comparison with the traditional methods, viz., compact tension (CT) and double cantilever beam (DCB) techniques for determination of K ISCC. However, the limited first K ISCC data, generated using CNT specimens have been queried for the lack of their comparison with the data generated by other techniques. This work presented here provides the first comparative results and validation for use of the novel CNT testing for generation of K ISCC data.

This thesis was scanned from the print manuscript for digital preservation and is copyright the a... more This thesis was scanned from the print manuscript for digital preservation and is copyright the author. Researchers can access this thesis by asking their local university, institution or public library to make a request on their behalf. Monash staff and postgraduate students can use the link in the References field.