What are the shortcomings of carbon steel performance?

With the development of science and technology and industry, higher requirements are put forward for materials, such as higher strength, high temperature, high pressure, low temperature, corrosion resistance, wear resistance and other special physical and chemical properties. Carbon steel can not fully meet the requirements.

Deficiency of carbon steel:
(1) Low hardenability. In general, the maximum quenching diameter of carbon steel is only 10 mm-20 mm.
(2) The strength and bending strength were lower. For example, the σ s of ordinary carbon steel Q235 is 235MPa, while that of Low Alloy Structural Steel 16Mn is more than 360MPa. The σ s / σ B of 40 steel is only 0.43, much lower than that of alloy steel.
(3) The tempering stability is poor. Due to the poor tempering stability, when the carbon steel is subject to tempering treatment, a lower tempering temperature is required to ensure a higher strength, so the toughness of the steel is low; in order to ensure a better toughness, the strength is low when the high tempering temperature is used, so the comprehensive mechanical property level of the carbon steel is not high.
(4) Can not meet the requirements of special performance. Carbon steel is often poor in oxidation resistance, corrosion resistance, heat resistance, low temperature resistance, wear resistance and special electromagnetic properties, which can not meet the requirements of special performance.