Do you want low carbon steel to withstand earthquakes? Low carbon means more ductile, right? Am I right?
There was a thread while ago where these differences in toughness/ductility and strength were addressed in some detail:physicsss said:Also, I don't understand what diffusion of concentration gradient is and what is the difference between toughness and strength. Is toughness also the hardness(stiffness)?
I'd go with Gokul's explanation on this one ... at high temperatures (= near the austenite transformation temperature) the nucleation rate is low, whilst the grain growth rate is high and vise versa at low temperatures. The resulting structures will then have characteristics which have resulted either from nucleation or growth dominated transformation processes (thinking about the extremes of ferrite - pearlite structures for example). So it is to great extent a matter of temperature dependency of diffusion and the greater driving force for nucleation the lower the temperature (the higher the undercooling).physicsss said:Can you explain to me how come as you lower the temperature on a isothermal transformation diagram for a eutectoid plain-carbon steel, you get finer and finer microstructures? Like you get as you lower it from coarse pearlite to fine pearlite to the finest bainite?
and read the articleA709 is the specification used for steel plate used in the manufacture of bridges. Chapel Steel stocks A709 Grade 36, A709 Grade 50 and A709 Grade 50W. These grades are often specified with charpy tests referencing the specific zone (or climatic region) in which the bridge will be in use. The charpys are specified as non-fracture critical which is a per heat test (frequency “H”), or fracture critical which is a per plate test (Frequency “P”). Bridge steels can also be ordered to the ASSHTO M270 Spec referenced as AASHTO M270 Grade 36, AASHTO M270 Grade 50, AASHTO M270 Grade 50W.