American standard carbon seamless steel pipes are tested for mechanical properties. The testing methods of mechanical properties are divided into two categories, one is tensile test and the other is hardness test.
Tensile testing is to make a seamless steel pipe into a sample, and use a tensile testing machine to pull the sample to the fracture point, and then measure one or more mechanical properties. Usually only tensile strength, yield strength, elongation and rate of reduction in area. Tensile test is the most basic method for testing metal mechanical properties. Almost all metal materials require tensile testing as long as they have mechanical property requirements. In particular, tensile testing is the only way to test the mechanical properties of materials whose hardness cannot be easily tested.
The hardness of 40Cr carbon seamless steel pipe can generally be tested by Rockwell hardness, and its hardness range is usually between HRC32-36 (that is, between HB301-340).
After quenching and tempering treatment, 40Cr steel has good comprehensive mechanical properties, low temperature impact toughness and low notch sensitivity, and the steel has good hardenability. In addition to quenching and tempering treatment, this kind of steel is also suitable for cyanidation and high-frequency quenching treatment, and has good cutting performance. 40Cr carbon seamless steel pipe is usually used to manufacture parts with small stress and high wear resistance requirements, such as machine tool spindles, bushings, gears, etc.
