The corrosion resistance of the developed 400 MPa grade rebar was evaluated by a series of experiments, including cycles of corrosion-accelerating tests in the simulated concrete pore solution and reinforced concrete ...The corrosion resistance of the developed 400 MPa grade rebar was evaluated by a series of experiments, including cycles of corrosion-accelerating tests in the simulated concrete pore solution and reinforced concrete cube corrosion-accelerating tests and in situ exposure experiments in chloride ions condition. In addition, the tensile and bending properties and the connection adaptability of the developed rebar were investigated. The results verify that the comprehensive properties of the corrosion-resistant rebar are excellent. The tensile and bending properties of the rebar are up to the standard of GB1499-2007. The common welding method and the mechanical connection technology of knob-cut roiled parallel thread splicing are suitable for the rebar.展开更多
Ni nanoparticles were coated uniformly on the surface of WC powder via a facile electroless plating method(abbreviated as WCN-EP),and then consolidated for mechanical and corrosion resistance performance characterizat...Ni nanoparticles were coated uniformly on the surface of WC powder via a facile electroless plating method(abbreviated as WCN-EP),and then consolidated for mechanical and corrosion resistance performance characterization,in comparison with hand mixed WC-Ni(WCN-H).Under the optimized electroless plating parameters,Ni particles,less than 1μm in average diameter,were found to be uniformly and densely wrapped on the surface of the tungsten carbide matrix of WCN-EP.In comparison,in WCN-H,the Ni particles about 1.8μm in average diameter,were randomly distributed together with irregular WC particles.The uniform coating of Ni was found to assist the densification process of WCN-EP effectively,with higher densities and less pores than those of WCN-H at the Ni content of 10.6wt%,25.5wt%,and 30.3 wt%.However,at the Ni content of 18.8wt%,the relative densities of WCN-EP and WCN-H both increased to the maximum value of 98%.The maximum hardness of the consolidated WCN-EP was 82.6 HRA,about 1.2 HRA higher than that of WCN-H.In addition,the consolidated WCN-EP also exhibits a superior corrosion resistance by the polarization curve analysis at an electrochemical workstation.展开更多
In this study, a 600 MPa hot-rolled corrosion-resistant steel plate produced by a specific company is investigated. Edge jagged defects and edge surface defects generated on both sides of the strip during production a...In this study, a 600 MPa hot-rolled corrosion-resistant steel plate produced by a specific company is investigated. Edge jagged defects and edge surface defects generated on both sides of the strip during production are characterized and analyzed. The results indicate that the distribution of reoxidation granules is located underneath the surface peel and that copper-containing granules diffuse along austenite grain boundaries. This phenomenon combined with the chemical composition and production parameters of a strip indicate that copper brittleness leads to edge jagged defects. However,the surface defects should be attributed to inherent defects on the surface of the strip. Measures that prevent surface oxidation and copper segregation at grain boundaries would likely eliminate these two types of edge defects.展开更多
基金Sponsored by National High-Tech Research and Development Program of China(2006AA03Z518)National KeyTechnology Research and Development Program in 11th Five-Year Plan of China(2007BAE30B05)
文摘The corrosion resistance of the developed 400 MPa grade rebar was evaluated by a series of experiments, including cycles of corrosion-accelerating tests in the simulated concrete pore solution and reinforced concrete cube corrosion-accelerating tests and in situ exposure experiments in chloride ions condition. In addition, the tensile and bending properties and the connection adaptability of the developed rebar were investigated. The results verify that the comprehensive properties of the corrosion-resistant rebar are excellent. The tensile and bending properties of the rebar are up to the standard of GB1499-2007. The common welding method and the mechanical connection technology of knob-cut roiled parallel thread splicing are suitable for the rebar.
基金Funded by the National Natural Science Foundation of China(Nos.51778213 and 52078189)the Fundamental Research Funds for the Central Universities of China(No.B200202073)。
文摘Ni nanoparticles were coated uniformly on the surface of WC powder via a facile electroless plating method(abbreviated as WCN-EP),and then consolidated for mechanical and corrosion resistance performance characterization,in comparison with hand mixed WC-Ni(WCN-H).Under the optimized electroless plating parameters,Ni particles,less than 1μm in average diameter,were found to be uniformly and densely wrapped on the surface of the tungsten carbide matrix of WCN-EP.In comparison,in WCN-H,the Ni particles about 1.8μm in average diameter,were randomly distributed together with irregular WC particles.The uniform coating of Ni was found to assist the densification process of WCN-EP effectively,with higher densities and less pores than those of WCN-H at the Ni content of 10.6wt%,25.5wt%,and 30.3 wt%.However,at the Ni content of 18.8wt%,the relative densities of WCN-EP and WCN-H both increased to the maximum value of 98%.The maximum hardness of the consolidated WCN-EP was 82.6 HRA,about 1.2 HRA higher than that of WCN-H.In addition,the consolidated WCN-EP also exhibits a superior corrosion resistance by the polarization curve analysis at an electrochemical workstation.
文摘In this study, a 600 MPa hot-rolled corrosion-resistant steel plate produced by a specific company is investigated. Edge jagged defects and edge surface defects generated on both sides of the strip during production are characterized and analyzed. The results indicate that the distribution of reoxidation granules is located underneath the surface peel and that copper-containing granules diffuse along austenite grain boundaries. This phenomenon combined with the chemical composition and production parameters of a strip indicate that copper brittleness leads to edge jagged defects. However,the surface defects should be attributed to inherent defects on the surface of the strip. Measures that prevent surface oxidation and copper segregation at grain boundaries would likely eliminate these two types of edge defects.
