1. After the steel is cold-worked hardened, its elastic modulus is basically unchanged. Generally speaking, when an external force is applied to an elastomer, the elastomer will change its shape (called "deformation"), and the general definition of "modulus of elasticity" is the stress in a unidirectional stress state divided by the strain in that direction.
2. The elastic modulus of steel remains unchanged after cold work hardening. Modulus of elasticity is an important performance parameter of engineering materials, from a macroscopic point of view, elastic modulus is a measure of the ability of an object to resist elastic deformation, and from a micro point of view, it is a reflection of the bond strength between atoms, ions or molecules.
3. After the steel is hardened by cold work, it is basically unchanged. Answer Correct choice: D Q&A At this time, the specimen is not broken, and can continue to be loaded, but it produces a large plastic deformation.
In the tensile test, the low carbon steel material specimen has been improved in the following four indexes after cold work hardening.
4. Q&A material mechanics mainly studies straight rods of equal cross-section, and also discusses some straight rods of variable cross-section and curved rods of equal cross-section. 1"Shear strain is the amount of change in the angle of any two micro-line segments in the component after deformation. "Answer: This statement is incorrect: Answer: The tangential strain is the amount of change in the angle between two orthogonal line segments of the element at a certain point.
1. In the cold plastic deformation of the metal, the indicators of the metal are strengthened, such as the yield point and hardness are improved, and the plastic indicators such as elongation are reduced, which is called cold work hardening. The boundary between cold and hot processing is the recrystallization temperature of the metal.
2. What is the mechanism of cold work hardening?That is, the cutting edge of the tool is not absolutely sharp, and it has a radius of arc of the tip r. Due to the existence of R, a thin layer of metal in the cutting layer cannot be cut into chips by the cutting edge and leave the workpiece, but is extruded and deformed by the arc radius r of the cutting edge of the cutting edge, and is left on the machining surface to form a ?h。
3. The cold work hardening process is a processing method that uses the cold work hardening of metal materials to improve the strength, hardness and wear resistance of metal materials. Examples of the use of this process are: sandblasting (to improve surface hardness, wear resistance), cold rolling (to increase the strength of the plate profile), cold tun (to increase the strength of bolts) and so on.
4. Cold work hardening is a common steel treatment method, which is widely used in the manufacturing industry. The principle of cold work hardening is to change the crystal structure of steel through plastic deformation. During cold working, the steel is subjected to external forces, and the grain boundary slip and dislocation motion in the crystal structure are activated, resulting in plastic deformation.
5. The main reason for cold work hardening is the slip and dislocation movement of metal crystals in the process of plastic deformation. Slip refers to the rearrangement and movement of atoms inside the crystal parallel to a certain crystal plane direction, resulting in plastic deformation of the crystal. A dislocation is a lattice defect in a crystal whose presence causes local strains and stress concentrations in the crystal.
6. Cold work hardening is an important process method for strengthening metal materials, and secondly, work hardening is also an important factor for workpieces to be formed. For example, the part of the cold-drawn steel wire that pulls through the die hole will no longer continue to deform due to the work hardening, and the deformation will be transferred to the part that has not been pulled through the die hole.