The strength and hardness of the precision seamless steel pipe
material increase, the plastic deformation recrystallization temperature, but the plasticity and toughness decrease. Also known as cold work hardening. The reason is that during the plastic deformation process of the precision seamless steel pipe, the grain is slipped, the dislocation entanglement, the slender, broken and fibrillated grain, and the residual stress generated by the internal precision seamless steel pipe. The degree of processing and processing of the surface layer and the depth of the hardened layer are usually expressed as compared to the hardness of the quenching.
Cold work hardening is a way to strengthen the precision seamless steel pipe and alloy with the process method (after the cold working, the strength is obviously improved after the decay or alloy), and then the cold stamping process is possible, which is beneficial to the formation and processing of the stainless steel pipe
. Alloy gold is not suitable for strengthening by heat treatment.
After cold drawing, rolling and shot peening can significantly improve the surface strength of precision seamless steel pipe materials, parts and components. This part of the stress, which often exceeds some part of the local stress of the material's yield limit, caused by plastic deformation, the development of plastic deformation due to work hardening constraints, can improve the safety of parts. The precision seamless steel pipe parts are transferred to the deformation of the surrounding non-hardened part accompanied by stamping and plastic deformation strengthening. By repeating the alternating cold stamping in this way, there is a uniform cross section.
Precision seamless steel tube cold work hardening can improve the cutting performance of low carbon steel, and the cutting is easy to separate. But the work of precision seamless steel tubes further difficult to harden. For example, cold drawn steel wire, due to work hardening, further energy-intensive painting, or even destroyed, it is necessary to eliminate work hardening by intermediate annealing, and then draw. When cutting the surface layer of the hard and brittle workpiece, and increasing the cutting speed of the cutting force, the tool wear and the like.
In most people's subconscious, precision steel pipes are considered to be rustless because of their precision. To be honest, the corrosion resistance of precision steel pipes is very good, so his cost performance is also relatively high, because the surface layer has a layer of film, which can reduce the possibility of oxidation.
However, due to the excessive laissez-faire of precision steel pipes, the maintenance of precision steel pipes will not be concerned. However, the precision steel pipe indicates that the weaker corrosion-resistant part of the film will form a pitting corrosion reaction due to the self-excited reaction, producing small pores, and will contain a strong corrosive solution with the adjacent chloride ions, accelerating corrosion. speed. In addition, the intergranular corrosion cracking inside the stainless steel destroys the film on the surface of the stainless steel plate. Therefore, the surface layer of the precision steel pipe should be cleaned and maintained at a certain level to better extend the service life of the precision steel pipe.