Electrochemistry experiments were made on carbon-manganese clean steel with rare earths Ce and La respectively to observe corrosion parameters such as corrosion current i_(corr), and characteristic potential of pittin...Electrochemistry experiments were made on carbon-manganese clean steel with rare earths Ce and La respectively to observe corrosion parameters such as corrosion current i_(corr), and characteristic potential of pitting E_b. The results indicate that the rare earths have effect on corrosion resisting properties of carbon-manganese clean steel, and the optimum contents of La is about 0.011% (mass fraction) and Ce about 0.014% (mass fraction) respectively. The change of corrosion resistance is related to the action of rare earths on microstructure and effect on surface state of samples in the process of polarization.展开更多
Using SEM and EDS some particles containing La and P were discovered in low oxygen and sulfur purity steel with lanthanum. In these particles low melting point elements such as As and Sb also were detected. According ...Using SEM and EDS some particles containing La and P were discovered in low oxygen and sulfur purity steel with lanthanum. In these particles low melting point elements such as As and Sb also were detected. According to the result of simulative calculation of segregation, it is shown that La and P enrich so strongly in the process of solidification that their concentrations can satisfy thermodynamic condition to forme LaP compound or meet the requirements to forme eutectic phase in the last stage of solidification. Therefore, the particles are concluded as LaP compound or eutectics, which exist on grain boundary mainly.展开更多
Adding lanthanum to carbon-manganese purity steel, the existing forms of lanthanum were investigated. The results show that enrichment on grain boundary and solid solution in cementite are two kinds of important exist...Adding lanthanum to carbon-manganese purity steel, the existing forms of lanthanum were investigated. The results show that enrichment on grain boundary and solid solution in cementite are two kinds of important existing forms of lanthanum relating to micro-alloyed action. As a result of enrichment of lanthanum, the concentration of lanthanum aggregated on somewhere of grain boundary reaches as high as tens of times of its average content although the average content is very low. In addition, lanthanum atoms can replace partial Fe atoms that constitute cementite to form alloyed cementite , the solid solution amount of lanthanum in alloyed cementite increases as the increase of its average content in purity steel.展开更多
The process of automotive spring steel in the basic oxygen furnace and ingot casting （BOF-IC） of Baosteel is described in this paper. High quality spring steel can be obtained through designing reasonable deoxidizat...The process of automotive spring steel in the basic oxygen furnace and ingot casting （BOF-IC） of Baosteel is described in this paper. High quality spring steel can be obtained through designing reasonable deoxidization and alloying processes ,enhancing steel purity and reducing inclusions in steel.展开更多
文摘Electrochemistry experiments were made on carbon-manganese clean steel with rare earths Ce and La respectively to observe corrosion parameters such as corrosion current i_(corr), and characteristic potential of pitting E_b. The results indicate that the rare earths have effect on corrosion resisting properties of carbon-manganese clean steel, and the optimum contents of La is about 0.011% (mass fraction) and Ce about 0.014% (mass fraction) respectively. The change of corrosion resistance is related to the action of rare earths on microstructure and effect on surface state of samples in the process of polarization.
基金Project supported by the Ministry of Science and Technology of China (2002BA315A-5)
文摘Using SEM and EDS some particles containing La and P were discovered in low oxygen and sulfur purity steel with lanthanum. In these particles low melting point elements such as As and Sb also were detected. According to the result of simulative calculation of segregation, it is shown that La and P enrich so strongly in the process of solidification that their concentrations can satisfy thermodynamic condition to forme LaP compound or meet the requirements to forme eutectic phase in the last stage of solidification. Therefore, the particles are concluded as LaP compound or eutectics, which exist on grain boundary mainly.
基金Project supported by the Ministry of Science and Technology of China (2002BA315A-5)
文摘Adding lanthanum to carbon-manganese purity steel, the existing forms of lanthanum were investigated. The results show that enrichment on grain boundary and solid solution in cementite are two kinds of important existing forms of lanthanum relating to micro-alloyed action. As a result of enrichment of lanthanum, the concentration of lanthanum aggregated on somewhere of grain boundary reaches as high as tens of times of its average content although the average content is very low. In addition, lanthanum atoms can replace partial Fe atoms that constitute cementite to form alloyed cementite , the solid solution amount of lanthanum in alloyed cementite increases as the increase of its average content in purity steel.
文摘The process of automotive spring steel in the basic oxygen furnace and ingot casting （BOF-IC） of Baosteel is described in this paper. High quality spring steel can be obtained through designing reasonable deoxidization and alloying processes ,enhancing steel purity and reducing inclusions in steel.
