Tensile properties of SS400 carbon steel plate

SS400 carbon steel plate is a representation of Japanese steel material and a judgment standard, equivalent to Q235 steel (also known as A3 steel) in China. Structural steel in foreign standards is often classified according to tensile strength, such as SS400 (as indicated in Japan), where 400 represents the minimum value of σb is 400MPa.

SS400 carbon steel plate specimen stretching: During the stretching process, the maximum force (Fb) that the material undergoes as it undergoes the yield stage and enters the strengthening stage, as the cross-sectional size decreases significantly, at the time of fracture, divided by the original cross-sectional area (So) of the specimen (σ), it is called tensile strength or strength limit (σb). The unit is Nmm2 (MPa). It represents the maximum resistance of metal materials to failure under tensile force. After yielding to a certain extent, due to the rearrangement of internal grains, their resistance to deformation is improved again. Although deformation develops rapidly at this time, it can only increase with the increase of stress until the maximum stress is reached. Afterwards, the ability of the steel to resist deformation significantly decreased, and the cross-section of the specimen rapidly decreased at the weakest point, leading to necking until fracture and failure. The maximum stress value of steel before tensile fracture is called the strength limit or tensile strength.