Reliability Study On Mechanical Property Of Adb610 Steel

Low-carbon bainitic steel ADB610 is a kind of steel which is a new generation of 610Mpa grade non-quenched steel succeed developed by Anshan Iron and Steel. It can substitute the same level of crack-free welding quenched and tempered WEL-TENCF62, NK-HITEN610U steel and other import steels. The steel has been used extensively in the penstock and volute of hydropower stations which achieved the localization of hydropower steel. As the hydropower penstock and volute to bear the dynamic load or underwater operation, which require 610MPa grade high strength low-alloy steel to ensure high strength while also have a good low-temperature impact toughness. Therefore, the study of the mechanical properties of ADB610 steel is of important significance for ensuring the safe operation of the steel structure.In this paper, the mechanical properties of ADB610 steel are tested, the tensile test, impact test by their mechanical properties-tensile strength, yield strength and impact energy are included. And these randomly distributed material properties of the measured datas are regard as random variables, mathematical statistical methods are used to deal with it.This paper are mainly researched on items listed below:First of all, the development, application, the mechanical properties and the chemical composition, the heat treatment and aging treatment process of ADB610 steel are discussed, The device of tensile test, impact test and specimen preparation methods of ADB610 steel are studied. Tensile test and impact test are taken, the obtained datas of mechanical properties are processed and recorded.Secondly, the distribution characteristics, parameters estimation and hypothesis testing of the commonly used statistical distribution functions, which includes the normal distribution, lognormal distribution, the two-parameter and three-parameter Weibull are programmed by MATLAB, and the corresponding linear regression are charted.Thirdly, statistical analysis for the tensile strength, yield strength, impact energy test data of different thickness of ADB610 steel plates are taken. The best distribution model is obtained, which in order to lay the foundation for reliability design.Fourthly, the thickness, aging treatment on mechanical properties of ADB610 steel are taken into account, the different thickness of the tensile strength, yield strength and impact energy test datas are comparative studied, and fore-and-aft aging treatment of the impact energy of ADB610 plate test data are also comparative studied. The conclusions are as follow:from a statistical point of view of Aging Treatment on Impact Toughness of Steel ADB610 does not significantly improved; when the difference of thickness is larger, the impact toughness of sheet metal plate is superior to the impact toughness;when the thickness is less, the difference is not significant.In the comparative study of low-temperature impact toughness of ADB610 steel and its replacement steel NK-HITEN610U Steel find out that the mean of ADB610 steel and NK-HITEN610U is no significant difference, but the latter data dispersion is greater, so the domestic steel ADB610 statistically superior to the imported steel NK-HITEN610U.Finally, in order to get to meet the credibility of the results of statistical analysis based on hypothesis-testing model, the confidence interval of the best distribution type on the parameters are studied.