45 steel heat treatment

       Quenching and tempering has a range of hardness, generally between 225-297HB. 45# steel is quenched and tempered, that is, quenching + high temperature tempering, the hardness should be at 297HB, that is, 31 ~ 32HRC! This is the most ideal state. This value may not be reached in general.

       45 steel quenching, if water quenching can generally reach 40----60HRC (according to water temperature and material size), quenching with oil is generally between 30----55HRC (depending on the thickness of the material and the type of quenching oil) ).
       There is no relationship between cracking and cracking and how much hardness is reached during the heat treatment, which is related to the shape of the workpiece and the heat treatment method.

       Medium and low carbon steels generally use normalizing. After the normalizing, the pearlite structure is obtained, which is convenient for cutting. High carbon steel, alloy steel is annealed (normal, spheroidized, isothermal.)

       Quenching and tempering is a double heat treatment of quenching and high temperature tempering, the purpose of which is to make the workpiece have good comprehensive mechanical properties.

       Quenched and tempered steel has two types of carbon quenched and tempered steel and alloy quenched and tempered steel. Whether it is carbon steel or alloy steel, its carbon content control is strict. If the carbon content is too high, the strength of the workpiece after quenching and tempering is high, but the toughness is not enough. If the carbon content is too low, the toughness is increased and the strength is insufficient. In order to obtain good overall performance of the tempering parts, the carbon content is generally controlled at 0.30~0.50%.

       During quenching and quenching, the entire section of the workpiece is required to be hardened, so that the workpiece is obtained by fine-stacked quenched martensite. By tempering at a high temperature, a microstructure mainly composed of uniform tempered sorbite is obtained. It is impossible for a small factory to conduct metallographic analysis for each furnace. Generally, it is only used for hardness testing. That is to say, the hardness after quenching must reach the quenching hardness of the material, and the hardness after tempering is checked according to the requirements of the drawing.
The operation of the workpiece quenching and tempering must be carried out strictly according to the process documentation. We only give some thoughts on how to implement the process during the operation.https://www.supplyforever.com/

45 steel hardness

       Commonly used medium carbon quenched and tempered structural steel. The cold plasticity of the steel is generally good. The annealing and normalizing are slightly better than the quenching and tempering. It has high strength and good machinability. After proper heat treatment, certain toughness, plasticity and wear resistance can be obtained. Convenience. Suitable for hydrogen welding and argon arc welding, not suitable for gas welding. Preheating is required before welding, and stress relief annealing should be performed after welding.

       Normalizing improves the cutting performance of blanks less than 160 HBS. After the steel is quenched and tempered, its comprehensive mechanical properties should be optimized for other medium carbon structural steels, but the steel has low hardenability, and the critical hardenability diameter in water is 12~17mm, and there is a tendency to crack when water quenching. When the diameter is more than 80mm, the mechanical properties are similar after quenching or tempering, and the medium and small mold parts can be quenched and tempered to obtain higher strength and toughness, while the large parts are treated with normalizing. Therefore, this steel is usually used in quenched or tempered condition.

       Quenching and tempering has a range of hardness, generally between 225-297HB. 45# steel is quenched and tempered, that is, quenching + high temperature tempering, the hardness should be at 297HB, that is, 31 ~ 32HRC! This is the most ideal state. This value may not be reached in general.

       45 steel quenching, if water quenching can generally reach 40----60HRC (according to water temperature and material size), quenching with oil is generally between 30----55HRC (depending on the thickness of the material and the type of quenching oil) ).https://www.supplyforever.com/