Development History Of Low Alloy Steel

The emergence of low alloy steel can be traced back to 1870 in the 19th century. A steel with a carbon content of 0.64-0.9% and a chromium content of 0.54-0.68%, a tensile strength of 685Mpa, and an elastic limit of 410Mpa was first used in engineering structures, and an arch bridge with a span of 158.5m was constructed. But this type of steel is not ideal and it is also very obvious that it requires post rolling heat treatment, is difficult to machine, and has poor corrosion resistance. Over the following century, countries around the world continued to explore and can generally divide low alloy steel into three different development stages with different characteristics, before the 1920s, from the 1920s to the 1960s, and after the 1960s. The first two stages can be collectively referred to as the traditional low alloy steel development stage, while the latter stage can be referred to as the modern low alloy steel development stage.