The flow behavior of Rene 95 PM alloy was studied from 1050 to 1150 deg Cwith strain rate of 1 X 10^(-3), 1 X 10^(-2), 1 X 10^(-1) and 1 s^(-1). At a given temperature andstrain rate, flow curves exhibit a peak follow...The flow behavior of Rene 95 PM alloy was studied from 1050 to 1150 deg Cwith strain rate of 1 X 10^(-3), 1 X 10^(-2), 1 X 10^(-1) and 1 s^(-1). At a given temperature andstrain rate, flow curves exhibit a peak followed by flow softening up to a steady state. Moreover,at constant strain, flow stress increases with increasing strain rate and decreasing temperature. Anequation relating hyperbolic sine of flow stress to hot working parameters, such as strain, strainrate and temperature, was established by using multiple nonlinear regression method. A very goodagreement was found between predicted and experimental flow stress in all the strain rangeinvestigated. Application of the constitutive equation in predicting forming loads and flow behaviorand temperature distribution in both upper and lower dies in an isothermal forging process ofturbine disk of large dimension (about 630 mm) by means of a finite element code was systematicallyanalyzed.展开更多
In the last two years or so,there has been increasing interest in hydrogen as an energy source in Australia[1–3]and around the world.Notably,this is not the first time that hydrogen has caught our collective interest...In the last two years or so,there has been increasing interest in hydrogen as an energy source in Australia[1–3]and around the world.Notably,this is not the first time that hydrogen has caught our collective interest.Most recently,the 2000s saw a substantial investment in hydrogen research,development,and demonstration around the world.Prior to that,the oil crises of the 1970s also stimulated significant investment in hydrogen,and earlier still,the literature on hydrogen was not lacking.And yet,the hydrogen economy is still an idea only.So what,if anything,might be different this time?展开更多
文摘The flow behavior of Rene 95 PM alloy was studied from 1050 to 1150 deg Cwith strain rate of 1 X 10^(-3), 1 X 10^(-2), 1 X 10^(-1) and 1 s^(-1). At a given temperature andstrain rate, flow curves exhibit a peak followed by flow softening up to a steady state. Moreover,at constant strain, flow stress increases with increasing strain rate and decreasing temperature. Anequation relating hyperbolic sine of flow stress to hot working parameters, such as strain, strainrate and temperature, was established by using multiple nonlinear regression method. A very goodagreement was found between predicted and experimental flow stress in all the strain rangeinvestigated. Application of the constitutive equation in predicting forming loads and flow behaviorand temperature distribution in both upper and lower dies in an isothermal forging process ofturbine disk of large dimension (about 630 mm) by means of a finite element code was systematicallyanalyzed.
文摘In the last two years or so,there has been increasing interest in hydrogen as an energy source in Australia[1–3]and around the world.Notably,this is not the first time that hydrogen has caught our collective interest.Most recently,the 2000s saw a substantial investment in hydrogen research,development,and demonstration around the world.Prior to that,the oil crises of the 1970s also stimulated significant investment in hydrogen,and earlier still,the literature on hydrogen was not lacking.And yet,the hydrogen economy is still an idea only.So what,if anything,might be different this time?
