1, # 45 steel a high-quality carbon structural steel, medium carbon steel, a carbon content of 0.4% or more, not high hardness and easy cutting, usually by hot-rolled or cold-rolled forming;
2, tensile strength > 686MPa, yield strength > 490MPa;
3, the quenched hardness between HRC20-HRC30, is quenched to ensure superior mechanical properties, but the surface hardness is low and not wear-resistant, and cutting performance will be reduced;
4, quenched hardness between HRC55-58, the limit value can reach HRC62, but will make the original mechanical properties reduced;
5, after carburizing treatment can improve the surface wear resistance;
6, the general use of quenching + surface quenching to adjust the hardness of the surface treatment of parts, making a good overall performance.
Commonly used surface treatment, heat treatment methods:
1, tempering;
2, quenching + surface quenching;
3, carburizing;
4, black zinc plating;
5、Chrome plating (hard chrome plating).
Disadvantages:
1, the surface is easy to rust, rust resistance is much worse than stainless steel and aluminum, and there are clean room requirements occasions can not be used.
Applications:
1, after tempering treatment is generally used for the manufacture of higher strength requirements, not very large force machined parts, forgings, stamping parts and nuts, pipe fittings, and other parts;
2, after carburizing treatment is generally used for the surface wear-resistant, core impact-resistant heavy-duty parts, gas wear resistance than quenched + surface quenching high.
