Phosphoric irons (i.e. Fe-P alloys containing low phosphorous in the range 0.1 to 0.7 wt. %) with/without addition of chromium were prepared by powder forging route. The corrosion behaviour of these alloys was studied...Phosphoric irons (i.e. Fe-P alloys containing low phosphorous in the range 0.1 to 0.7 wt. %) with/without addition of chromium were prepared by powder forging route. The corrosion behaviour of these alloys was studied in different environments. The various environments chosen were acidic (0.25 M H2SO4 solution of pH 0.6), neutral/marine (3.5 % NaCl solution of pH 6.8) and alkaline (0.5 M Na2CO3 + 1.0 M NaHCO3 solution of pH 9.4). The corrosion studies were conducted using Tafel Extrapolation and Linear Polarization techniques. The results were compared with the corrosion resistance of electrolytic Armco iron. It was observed that, chromium improved the resistance to corrosion in marine conditions only. Corrosion rates were higher in acid medium due to the enhanced hydrogen evolution and hence, the cathodic reaction. The corrosion rates were minimal in alkaline medium and low in neutral solution.展开更多
Phosphorous is widely considered as an impurity in steels. Consequently, its role as an important alloying element in iron could never be established. The present paper deals with the exploitation of phosphorous as a ...Phosphorous is widely considered as an impurity in steels. Consequently, its role as an important alloying element in iron could never be established. The present paper deals with the exploitation of phosphorous as a useful alloying element in iron in conjunction with carbon by way of improved thermo-mechanical processing leading to a tough steel equivalent to high strength low alloy steels. It was observed that phosphorous is pushed towards ferrite grains by carbon which in turn forms pearlite along ferrite grains. Suitable adjustment in the amounts of carbon and phosphorous yields an attractive set of mechanical properties after appropriate processing. Typical chemistry and processing combinations yields UTS: 700 MPa and % El: 25% Area under the stress-strain curve: 60 Joules.展开更多
文摘Phosphoric irons (i.e. Fe-P alloys containing low phosphorous in the range 0.1 to 0.7 wt. %) with/without addition of chromium were prepared by powder forging route. The corrosion behaviour of these alloys was studied in different environments. The various environments chosen were acidic (0.25 M H2SO4 solution of pH 0.6), neutral/marine (3.5 % NaCl solution of pH 6.8) and alkaline (0.5 M Na2CO3 + 1.0 M NaHCO3 solution of pH 9.4). The corrosion studies were conducted using Tafel Extrapolation and Linear Polarization techniques. The results were compared with the corrosion resistance of electrolytic Armco iron. It was observed that, chromium improved the resistance to corrosion in marine conditions only. Corrosion rates were higher in acid medium due to the enhanced hydrogen evolution and hence, the cathodic reaction. The corrosion rates were minimal in alkaline medium and low in neutral solution.
文摘Phosphorous is widely considered as an impurity in steels. Consequently, its role as an important alloying element in iron could never be established. The present paper deals with the exploitation of phosphorous as a useful alloying element in iron in conjunction with carbon by way of improved thermo-mechanical processing leading to a tough steel equivalent to high strength low alloy steels. It was observed that phosphorous is pushed towards ferrite grains by carbon which in turn forms pearlite along ferrite grains. Suitable adjustment in the amounts of carbon and phosphorous yields an attractive set of mechanical properties after appropriate processing. Typical chemistry and processing combinations yields UTS: 700 MPa and % El: 25% Area under the stress-strain curve: 60 Joules.
