40cr alloy plate characteristics: medium carbon modulation steel, cold heading die steel. 40cr alloy steel is easy to process, and certain toughness, plasticity and wear resistance can be obtained after proper heat treatment. Normalizing can promote the spheroidization of the structure and improve the cutting performance of the blank with a hardness of less than 160HBS.
The main role of Cr in the heat treatment of
45 #steel is to improve the hardenability of the steel. Due to the improved hardenability, the mechanical properties of 40Cr after quenching (or quenching and tempering), such as strength, hardness, and impact toughness, are also significantly higher than those of 45# steel. But also because of the strong hardenability, the internal stress of 40Cr during quenching is larger than that of 45# steel. Under the same conditions, the cracking tendency of the workpiece of 40Cr material is greater than that of the workpiece of 45# steel material. Therefore, in order to avoid the cracking of the workpiece, the oil with lower thermal conductivity is mostly used as the quenching medium during 40Cr quenching (sometimes the double-liquid quenching method is also used, as the saying goes, water quenching oil cooling), while 45# uses water with higher thermal conductivity as the quenching medium. medium.
After
quenching and low temperature tempering, the 40cr alloy plate is used to manufacture parts with heavy load, low impact and wear resistance, and the solid thickness on the section is below 25mm, such as worms, spindles, shafts, collars, etc. After quenching and tempering and high-frequency surface quenching, it is used to manufacture parts with high surface hardness and wear resistance without great impact, such as gears, sleeves, shafts, main shafts, crankshafts, spindles, pins, connecting rods, Screws, nuts, intake valves, etc. In addition, this steel is suitable for manufacturing various transmission parts for carbonitriding treatment, such as gears and shafts with larger diameters and good low temperature toughness.
