I'm a tech creator
Carbon (C), nitrogen (N), oxygen (O), sulfur (S), phosphorus (P), nickel (Ni), etc., have different effects on the impact absorption work or brittleness of steel at low temperatures.
1) Carbon (c) occurs as carbide in steel, which is the source of brittleness of steel, and its effect on the impact absorption work of non-alloy steel is shown in Figure 1
Figure 1 Effect of carbon content on the impact absorption work of unalloyed steels.
2) The effect of nitrogen (n) on the brittleness transition temperature of steel is shown in Figure 2
Figure 2: Effect of nitrogen content on steel brittleness transition temperature.
3) Oxygen (O) is one of the elements that cause intergrain embrittlement in steel, and the content of oxygen (O) in steel should be reduced as much as possible. The brittleness transition temperature of oxygen(o) to steel is shown in Figure 3
Figure 3: Effect of oxygen content on steel brittleness transition temperature.
4) Sulfur (S) exists in the form of inclusions in steel, and the presence of sulfur (S) does not affect the brittle transition temperature of the steel, but reduces the impact toughness of the steel;
5) Phosphorus (P) is also an element that promotes the low-temperature brittleness of steel, and the content of phosphorus (P) should be reduced as much as possible to improve the impact toughness of steel
6) Nickel (Ni) can improve the low-temperature toughness of steel, and with the increase of nickel (Ni) content in the steel, the low-temperature toughness also increases, as shown in the figure below
Figure 4 Effect of nickel content on the impact absorption work of mild steel.