Plasticity: Plasticity refers to the ability of a metallic material to produce plastic deformation (permanent deformation) without destruction under load.
Hardness: hardness is a measure of the degree of soft and hard metal materials pointer. Currently in production to determine the hardness of the most commonly used method is the indentation hardness method, which is a certain geometric shape of the indenter under a certain load pressed into the surface of the metal material being tested, according to the degree of being pressed into the determination of its hardness value.
Commonly used methods are Brinell hardness (HB), Rockwell hardness (HRA, HRB, HRC) and Vickers hardness (HV) and other methods.
Strength: Strength is the performance of a metallic material to resist damage (excessive plastic deformation or fracture) under static load. Due to the action of the load in the form of tensile, compression, bending, shear, etc., so the strength is also divided into tensile strength, compressive strength, bending strength, shear strength. There is often a certain connection between the various strengths, the use of tensile strength is generally more as the most basic strength pointer.
Fatigue: the strength, hardness, plasticity discussed earlier are metals under static load mechanical properties pointer.
In fact, many machine parts are working under cyclic loads, under such conditions parts will produce fatigue.
Welding: high-frequency straight seam welding, Q345B seamless square tube (extruded from Q345B seamless round tube).
Toughness: the load acting on the machine parts at a great speed is called impact load, the ability of the metal to resist damage under the action of impact load is called impact toughness.