Economic and environmentally friendly method for producing invar steel wire rod coils

Abstract

The invention relates to an economic and environmentally friendly method for producing invar steel wire rod coils. The method comprises the following steps: hot rolling is performed on a wire rod without pickling, direct scalping is carried on the wire rod; the wire rod coils after hot rolling are hanged with lubrication ash without pickling, cold drawing is carried out until the material is round, and then the material is introduced into a scalping machine. The cold drawn wire rod is sent to an annealing furnace for annealing, an atmosphere cover-type protection furnace is used for annealing, the annealing temperature is 920-940 DEG C, the insulation time is 2.5-3.5 hours, cooling in furnace is carried out to lower than the temperature of 200 DEG C and then tapping is carried out, then the material is straightened by the scalping machine, and then radial scalping with 0.95-1.1 mm is carried out. The method has the advantages of simple operation, safety and environmental protection, invisible depreciation cannot be formed, the waste material after scalping is recovered and reused, the utilization rate of the material is increased, production cost of the material is reduced, and the competitiveness of the product in the market is increased.

Description

technical field [0001] The invention relates to a production method of Invar's cold heading and hot-rolled wire rod discs which improve the surface quality of Invar's cold-heading and hot-rolling wire coils (Invar cold-heading and hot-rolling wire coils). A new environmentally friendly surface treatment method. Background technique [0002] Invar is an iron-based high-nickel alloy, which usually contains 32-36wt% Ni, a small amount of S, P, C and other elements, and the rest is about 60wt% Fe. Since nickel is an expanded austenite element, it is high-nickel. The phase transformation from austenite to martensite is lowered below room temperature, -100°C to -120°C. Therefore, after annealing, Invar has a face-centered lattice structure within a certain temperature range of room temperature and below room temperature. The austenite structure is also a solid solution formed by dissolving nickel in γ-Fe, so invar has excellent properties such as small expansion coefficient, low ...

AI Technical Summary

Problems solved by technology

The advantages of this traditional surface treatment method are low investment and simple equipment, but the risks and invisible losses are very large, which greatly increases the production cost of Invar, which leads to the increase of the total production cost of Invar products and reduces the product quality. Market Competitiveness

[0005] The main risks are: 1) If the hot-rolled black-skin Invar cold-heading billet is immersed in the acid solution, if you do not pay attention to it, the material may be damaged by acid. , forming dense pits and pits, resulting in that the pits and pits cannot be completely eliminated when the finished product is drawn, affecting the surface quality of the finished product and causing the product to be scrapped

What is more serious is that the material is in the acid solution. Due to the inappropriate acid ratio and wrong operation, the actual work experience of the workers is insufficient, and the pickling time is not well grasped, the grain structure in the material is eroded and destroyed by the acid solution, causing the surface of the material to be damaged. Severe erosion, even the material is directly brittle, and cannot enter the next drawing process at all

This pickling process requires the operator to have very high technology and skilled skills, as well as long-term work experience, and has high requirements for the safety and environment of the operation.

[0006] 2) The treatment of waste acid after pickling requires a high cost. If it is not treated or not treated properly, it will be discharged directly, which will easily pollute the environment. In serious cases, it may violate the law, so the risk is still very high

[0007] 3) A little carelessness or improper operation by workers can easily cause major safety production accidents and bring huge economic losses to the enterprise.

[0008] 4.) Due to the pickling, oxide scales, etc. are dissolved in the acid solution, resulting in an increase in the invisible loss of the material cost. The invisible loss of the pickling of the general Invar hot-rolled billet is 3%, and the nickel element in the material also enters the In the waste acid, it is not recyclable, which leads to a serious waste of social nickel resources, and also increases the production cost of cold heading Invar products, reducing the market competitiveness of products

[0009] 5) Pickled hot-rolled discs have many defects on the surface other than oxide skin, such as warped skin, phosphorus skin, cracks, burrs and many other defects that affect cold-drawn products. To eliminate these defects, only in After pickling, use the method of manually adding an angle grinder to grind it bit by bit. This is time-consuming and labor-intensive, and because it is manual grinding, the quality of the grinding wire is often affected by the technical level and quality of the workers. As a result, the quality of the final product is affected. At the same time, because it is manually polished, the work efficiency is very low, and it is not suitable for the drawing production of large quantities of cold heading Invar materials.