Straight seam steel pipe products are widely used in tap water projects, the petrochemical industry, the chemical industry, the power industry, agricultural irrigation, and urban construction. They are one of the 20 key products developed in my country. Straight seam steel pipes are used for liquid transportation: water supply and drainage. Straight seam steel pipes are used for gas transportation: coal gas, steam, and liquefied petroleum gas. Straight seam steel pipes are used for structures: such as piling pipes, bridges; docks, roads, building structures, etc. The comparison of die-casting techniques and reagents for straight seam steel pipes is content that users need to understand. The following is a detailed introduction:
1. Straight seam steel pipe casting steel: a pressure processing method that uses the reciprocating impact force of the forging hammer or the pressure of the press to change the blank into the shape and size we need.
2. Extrusion: It is a processing method in which the steel puts the metal in a closed extrusion cylinder, applies pressure at one end, and squeezes the metal out of the regular die hole to obtain a product with the same shape and size. It is mostly used to produce non-ferrous metal steel.
3. Straight seam steel pipe rolling: the steel metal billet is passed through the gap (various shapes) of a pair of rotating rollers, and the compression of the rollers reduces the material cross-section and increases the length.
4. Drawing steel: It is a processing method that pulls the rolled metal billet (profile, tube, product, etc.) through the die hole to reduce the cross-section and increase the length. Most of them are used for cold processing.
The die-casting technology of straight seam steel pipe metal is no longer a secret. As early as the 1930s, the West had discovered that steel could be deformed by rolling like other softer non-ferrous metals. This new technology was quickly promoted as soon as it was launched. Because its technology is simple and easy to learn, the production equipment and basic costs are very low, and the straight seam steel pipes produced are rich and diverse, reliable, and have a wide range of uses, the upgrading of technology has attracted the attention of scientific researchers. About ten years later, a British company successfully developed a glass lubricant, which made the straight seam steel pipe rolling technology quickly popular in various countries.
Before this, the traditional steel pipe rolling production technology used graphite as a lubricant. However, graphite lubricant has its fatal disadvantages:
1. High heat transfer efficiency, poor insulation, fast mold heating, fast wear, and difficult-to-roll long products.
2. The carbon content of the product is high. When producing stainless steel, intergranular corrosion is easy to occur. Therefore, the carburized layer must be removed after completion, which increases the cost.
3. Increased ecological pollution damage.
Compared with graphite lubricants, the advantages of glass lubricants for straight seam steel pipes are:
1. Glass has low heat transfer efficiency, the insulation work on the surface of the workpiece is well done, and the service life of the mold is guaranteed.
2. The lubrication capacity is three times higher than that of graphite, and the production speed and width are correspondingly increased, so the scale of products produced by the rolling machine can be expanded.
3. The chemical properties of glass lubricants are stable and will not cause structural defects.
4. The concentration of glass can be adjusted at will to obtain different physical properties (such as softening point, viscosity, etc.) to meet the needs of rolling products of different materials.
5. Clean and environmentally friendly, with no side effects and little damage to the environment.
In summary, the glass lubricant has excellent product performance and is a lubricant for the production of straight seam steel pipes. Three ways to ensure smoothness as required when producing straight seam steel pipes are:
1. Rolling mold: The general practice of rolling mold lubrication is to press glass powder into glass pads. Before the straight seam steel pipe is rolled, the glass pad is clamped between the steel and the rolling mold. To make the glass pad soften to the best extent under the action of center friction, the shape of the manufactured glass pad matches the shape of the rolling mold inlet cone and the end of the steel.
2. Rolling cylinder and mandrel: The glass agent used for the lubrication of the rolling cylinder and mandrel is powdered, with small particles and a high softening degree, and then applied to the inner hole and outer surface of the steel. In addition, it is also possible to wrap glass cloth around the surface of the steel and wrap the glass cloth strip around the mandrel.
3. Removal of glass film on the surface of steel pipe: Because glass lubricant is used during rolling, a thin layer of glass film will remain on the inside and outside of the rolled steel pipe. This film is the same as ordinary glass, hard and brittle, which will affect the products after use, so it must be removed. There are mechanical and chemical methods for removal. Mechanical methods can be used by shot peening, water cooling, and stretching straightening. If the chemical method is used to remove the glass film, we all know that the chemical properties of glass are quite stable, so if the chemical method is used, strong acid or strong alkali liquid is used. However, the damage of the pickling method is that it is highly corrosive to various steel pipe materials, which may cause the surface of the steel pipe to be over-picked, especially for carbon steel. It is not cost-effective and inappropriate to use pickling alone. Therefore, most of them now use the acid-base combined removal method.
Post time: Jan-15-2025