The process of changing the internal structure (or the chemical composition of the surface layer) of metal parts through a certain process of heating, heat preservation and cooling is called heat treatment.
Many machine parts and engineering components are subject to various heat treatments. The main purpose is to:
）So that the workpiece can obtain a good process, so that all kinds of processing can be carried out smoothly.
）The mechanical properties (or physical and chemical properties) required by the design shall be given to the workpiece to enable it to work normally, improve the service life and reduce the cost. The wire rod belongs to the section steel according to its cross-section shape, and has actually become an independent steel class. Hot rolled round steel with diameter of 5-4mm and deformed steel bar less than 10mm are generally called wire rod. Most of the wire rod is supplied by coiling machine, so it is also called wire rod or coil.
Basic knowledge of spring:
Springs are widely used for energy storage, vibration reduction, force measurement, etc. In electrical appliances, springs are often used to ensure good contact or separation of conductive parts.
There are many kinds of springs, including spiral spring, volute spring, leaf spring and leaf spring. Among all kinds of springs, the common cylindrical spiral spring is the most common. The type, end structure and technical requirements of the spring are specified in GB / T 1239-1984. Its size series is also specified in GB / T 1358-1993.
The names of each part of the cylindrical spiral compression spring and their relationship are listed in the table below.
Name and basic parameters of each part of cylindrical spiral compression spring:
The name and symbol indicate the diameter of the profile d the material used to make the spring diameter the outer diameter of the spring d the maximum diameter of the spring the inner diameter of the spring D1 the minimum diameter of the spring the effective number of the middle diameter of the spring n in order to work smoothly, n is generally not less than 3 turns, the number of supporting rings N0, the two ends of the spring are tightly and ground flat (or forged), and the total number of coils (generally 1.5, 2 or 2.5 turns) only plays a supporting or fixing role The axial distance from the corresponding points on the two adjacent effective coils H0 the spring height developed length L when not under load l the length of steel wire required for spring manufacture L ≈ π. The dimensions of D, D, t, H0, N, l of cylindrical spiral compression spring have been specified in GB / T 2089-1994. The standard can be consulted when using.
Wire rod is mainly used as reinforced concrete reinforcement and welding structural parts or raw materials for reprocessing (such as wire drawing, drawing, etc.). According to the steel distribution catalogue, wire rod includes ordinary low carbon steel rolling wire rod, electric welding wire rod, blasting wire rod, Quenched and Tempered Threaded wire rod and high quality wire rod. The widely used wire rod is common low carbon steel hot rolling wire rod, also known as common wire rod. It is made of Q195, Q215, Q235 ordinary carbon steel, with nominal diameter of 5.5-14.0 mm, and the weight of each plate is 100-200 kg. Now, it is mostly rolled on the torsion free high-speed wire rod mill and controlled cooling after rolling. The diameter is 5.5-22.0 mm, and the maximum coil weight can reach 2500 kg. Common wire rod is mainly used in construction, wire drawing, packaging, welding rod and manufacturing bolts, nuts, rivets, etc. High quality wire rod, only supply high quality carbon structural steel hot rolled wire rod. Such as 08F, 10, 35MN, 50Mn, 65, 75MN, etc. Used as raw material of steel wire and other metal products and other structural parts, as well as wire rod for rolling other high quality steel. It is customary to list high-quality profiles above 8mm and metal products below 8mm.
Wire rod is one of the most widely used steel products. After rolling, it can be directly used for reinforcement and welding structural parts of reinforced concrete, and can also be used for reprocessing. For example, it is drawn into various specifications of steel wire, then twisted into wire rope, woven into wire mesh, wound and heat treated into spring; through hot and cold forging, rivets, cold forging and rolling into bolts and screws; after cutting into heat treatment, mechanical parts or tools are made.
The wire rod is generally made of ordinary carbon steel and high quality carbon steel. According to the steel distribution catalogue and different uses, wire rod includes ordinary low carbon steel hot-rolled rod, high-quality carbon steel wire rod, carbon electrode wire rod, Quenched and Tempered Threaded wire rod, wire rod for wire rope, wire rod for piano wire and stainless steel wire rod.
Ordinary low carbon steel hot-rolled disk rod (gb701-65), which is rolled by low-carbon common carbon structural steel or carbon structural steel with low yield point, is the wire rod with the largest consumption and the most widely used in wire rod varieties, so it is also called common wire rod, referred to as common wire rod.
Main uses: the general line is mainly used for reinforced concrete structure of building, and can also be made into steel wire by cold drawing and used for binding.