Shenzhen Shengjinlong Iron and Steel Co., Ltd.

company's product
Home > news > Content

Characteristics and classification of profiles produced by Shenzhen profile manufacturers

Profiles in Shenzhen profile manufacturers refer to solid straight strips of metal that have been plastically shaped and have a certain cross-sectional shape and size. Profiles have a wide variety of specifications and versatility, and they occupy a very important position in rolling production.

The profile is an object of a certain geometry made of iron or steel and a material having a certain strength and toughness by rolling, extrusion, casting, and the like. These materials have a certain size and a certain shape, and have a certain mechanical and physical properties. Profiles can be used separately or further processed into other manufactured products, often used in building structures and manufacturing installations. Mechanical engineers can select the specific shape, material, heat treatment state, mechanical properties and other parameters of the profile according to the design requirements, and then divide the profile according to the specific size and shape requirements, and then further processing or heat treatment to meet the design accuracy requirements. The material, specifications and dimensions of the profiles can be referred to the corresponding national standards.

The profiles produced by Shenzhen profile manufacturers have the following characteristics: (1) Variety of specifications. More than 10,000 kinds have been produced, and in the production, except for a few special rolling mills to produce special products, most of the profile rolling mills are producing in multiple varieties and specifications.

(2) The difference in cross-sectional shape is large. In profile products, except for the simple and uneven shape of square, round and flat steel sections, most complex section profiles (such as angle grooves, H-beams, double-word steel, channel steel, rails, etc.) are not only complex in cross-section shape. Moreover, the difference between each other is large. The hole design and rolling production of these products have their particularities; the complexity of the cross-section shape makes the deformation of various parts of the metal, the temperature distribution of the section and the wear of the rolls during the rolling process. Uniform, so the size of the rolling stock is difficult to accurately calculate and control, the rolling mill adjustment and the installation of the guiding device are also complicated; in addition, the individual varieties or specifications of the complex section profiles are usually small in size. The above factors make the development of complex section profile rolling technology difficult.

(3) The structure of the rolling mill and the layout of the rolling mill are many. In the structural form, there are a two-roll mill, a three-roll mill, a four-roll universal hole mill, a multi-roll mill, a Y-roll mill, a 45-roll mill, and a cantilever mill. In the rolling mill arrangement, there are a row rolling mill, an in-line rolling mill, a checkerboard rolling mill, a semi-continuous rolling mill and a continuous rolling mill.

There are five main classification methods for profiles:

(1) According to the production method, the type materials can be divided into hot-rolled profiles, cold-formed profiles, cold-rolled profiles, cold-drawn profiles, extruded profiles, forged profiles, hot-bent profiles, welded profiles and special rolled profiles according to the production method.

(2) According to the characteristics of the section, the sections can be divided into simple section profiles and complex section profiles according to their cross-sectional shape. The cross-section of the simple section profile is symmetrical, the shape is relatively uniform and simple, such as round steel, wire, square steel and silicon steel. Complex section profiles, also known as profiled sections, are characterized by a distinct convex-concave branch in cross section. Therefore, it can be further divided into flange profiles, multi-step profiles, wide and thin profiles, partially special processed profiles, irregular curved profiles, composite profiles, periodic section profiles and wire materials, and the like.

(3) According to the use department, the types of materials are classified according to the use department (rails, fishplates, ballasts, wheels, wheels), automotive profiles (rims, tire retaining rings and lock rings), shipbuilding profiles (L-shaped steel, ball flat steel, Z-shaped steel, marine window frame steel), structural and architectural profiles (H-beam, I-beam, channel steel, angle steel, crane rails, window frames and door frames, steel sheet piles, etc.), Mining steel (U-shaped steel, channel steel, mining I-beam, scraper steel, etc.), machinery manufacturing profiles, etc.

(4) According to the size of the section, the sections can be divided into large, medium and small profiles according to the section size. The division is usually classified by rolling them on large, medium and small rolling mills. The distinction between large, medium and small is actually not strict. There is also a method of distinguishing by single weight (kg/m). It is generally considered that small materials with a weight of 5 kg/m or less are medium-sized materials with a single weight of 5 to 20 kg/m, and large materials with a single weight of more than 20 kg/m.

The concept of blanking has two implications: initial rolling and secondary blanking. The initial rolling is a large billet required for the steel mill to pass through a small number of heavy steel billets produced by steel making. The secondary blanking is to further roll the virgin blank of the section into a small billet and supply it to a rolling mill. The blanking process is shown in Figure 1.

The purpose of heating and rolling heating is to reduce the deformation resistance of the metal, improve the plasticity of the metal, and improve the texture of the structure. Profile rolling is divided into rough rolling, medium rolling and finishing rolling. The task of rough rolling is to roll the billet into a suitable blank intermediate billet. In the rough rolling stage, the rolling stock temperature is high, and the uneven deformation should be placed as much as possible in the rough rolling type rolling stage. The task of the medium rolling is to make the rolling stock extend quickly and approach the finished product size. Finishing is to ensure the dimensional accuracy of the product, and the amount of extension is small. The elongation coefficients of the finished hole and the front hole are generally 1.1 to 1.2 and 1.2 to 1.3, respectively. Modern steel production usually has the following requirements for the rolling process: (1) A blank of one size is rolled into a plurality of intermediate blanks in the rough rolling stage. The rough rolling of the section steel is generally carried out in a two-roll hole type. If the steel billet is entirely made of continuous casting billet, from the production organization of steel making and continuous casting, the smaller the size of the continuous casting billet, the better. It is better to only require one specification. The more the size specifications of the finished steel products, the stronger the company's ability to open up the market. This requires rough rolling to have the ability to open a blank into a variety of blanks. In the rough rolling, the profiled blank can be expanded and expanded, or the waist can be rolled. A more typical example is the rolling of H-beams from slabs. (2) For profiled materials, use 10,000 holes and multi-roller holes as much as possible during the medium and finish rolling stages. Since the multi-roll hole type and the universal hole type are favorable for rolling thin and high sides, and it is easy to individually adjust the reduction amount of each part on the section of the rolled piece, the uneven wear of the rolls can be effectively reduced, and the dimensional accuracy can be improved. (3) Continuous rolling of section steel, due to the large section coefficient of the rolled piece, the looper cannot be used. The tension control of the rack is generally carried out by using the current memory method of driving the main motor or the torque memory method. (4) For most steels, low temperature toughness and good weldability are generally required in use. To ensure these properties, the carbon equivalent is required in the material. For these steels, low temperature heating and low temperature rolling can refine the grains and improve the mechanical properties of the materials. Water cooling after finish rolling also has significant benefits in improving material properties and reducing cooling time on a cold bed.

There are two kinds of processes for finishing after finishing of the finished profile, one is the traditional hot sawing and cutting ruler, the fixed length straightening process, and the other is the newer long-length cooling, long straightening and cold sawing process. . Finishing of the profile, the more prominent is the straightening. The straightening difficulty of the profile is greater than that of the plate and the pipe, because the bending is large due to the asymmetry of the section and the uneven temperature during the cooling process; the second is that the section coefficient of the profile is large, and the required straightening force is large. Due to the large section of the rolled piece, the roll distance of the straightening machine must also be large, and the straightening blind zone is large. Under some conditions, the use of the steel material is greatly affected. For example, the straightening blind zone of the heavy rail is significantly reduced. The full-length flatness of the heavy rail. To reduce the straightening blind zone, the measure on the equipment is to use a variable intercept straightening machine, and the technical measure is long straightening.

Shenzhen Shengjinlong Iron & Steel Co., Ltd. is a large-scale warehouse-operated trading company specializing in the sale of steel products. It has a large-scale yard, a large number of stocks, and complete specifications. You are welcome to consult.