12CrNi3 steel belongs to alloy carburized steel and has higher hardenability than 12CrNi2A steel. Therefore, it can be used to manufacture parts with a slightly larger cross-section than 12CrNi2A steel.
The steel has good comprehensive mechanical properties after quenching, low-temperature tempering, or high-temperature tempering. The steel has good low-temperature toughness, small notch sensitivity, and good cutting performance. When the hardness is HB260-320, the relative cutting ability is 60%~70. In addition, the steel has low hardness and good plasticity after annealing. Therefore, it can be manufactured by either cutting or cold extrusion forming methods. To improve the wear resistance of the mold cavity, carburization treatment is required after the mold is formed, followed by quenching and low-temperature tempering to ensure that the surface of the mold has high hardness and wear resistance, while the core has good toughness. This steel is suitable for manufacturing large and medium-sized plastic molds. But the steel has temper brittleness tendency and white spot tendency.
Characteristics and Scope of Application
It is a high-grade carburized steel with a wide range of uses. Compared with 15Cr and 20Cr steels, it has higher strength, plasticity, and hardenability. Mainly used to produce spindles that require high strength, hardness, and toughness under heavy load conditions, as well as shafts and rods that require high center toughness or withstand impact loads, surface wear resistance, and small heat treatment deformation, as well as various transmission gears, adjusting screws, and camshafts that work under high-speed and impact loads
chemical composition
Carbon C: 0.10~0.17
Silicon Si: 0.17-0.37
Manganese Mn: 0.30~0.60
Sulfur S: allowable residual content ≤ 0.035
Phosphorus P: allowable residual content ≤ 0.035
Chromium Cr: 0.60-0.90
Nickel: 2.75-3.15
Copper Cu: allowable residual content ≤ 0.030