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Dikişsiz çelik borular yaygın olarak kullanılmaktadır.. The general-purpose dikişsiz çelik boru is rolled from ordinary carbon structural steel, Düşük alaşımlı çelik konstrüksiyon veya alaşımlı çelik konstrüksiyon. .2. Farklı kullanımlara göre, üç kategoriye ayrılmıştır: bir. Kimyasal bileşime ve mekanik özelliklere göre; b. Mekanik özelliklere göre; C. Hidrolik teste göre. a ve b kategorilerine göre tedarik edilen çelik borular, if they are used to withstand liquid dynamics, ayrıca bir hidrostatik teste tabi tutulacaktır. 3. Özel amaçlar için birçok dikişsiz boru çeşidi vardır., kazanlar için dikişsiz borular gibi, jeolojik kullanım için dikişsiz borular ve petrol için dikişsiz borular.
Kaynaklı çelik boru, also known as welded pipe, is a steel pipe made of steel plate or steel strip after being crimped and welded. Welded steel pipe has a simple production process, yüksek üretim verimliliği, many varieties and specifications, and less equipment, but the general strength is lower than that of seamless steel pipe. Since the 1930s, with the rapid development of continuous rolling production of high-quality strip steel and the advancement of welding and inspection technology, the quality of welds has been continuously improved, the varieties and specifications of welded steel pipes have been increasing, and more and more fields have replaced non-ferrous steel. Seam steel pipe.
Welded steel pipes are divided into straight seam welded pipes and spiral welded pipes according to the form of the weld. The production process of straight seam welded pipe is simple, the production efficiency is high, the cost is low, and the development is fast. The strength of the spiral welded pipe is generally higher than that of the straight seam welded pipe. ancak, compared with the straight seam pipe of the same length, the length of the weld is increased by 30-100%, and the production speed is lower. bu nedenle, the welded pipes with smaller diameters are mostly straight seam welded, and the welded pipes with large diameters are mostly spiral welded.
In the appearance of the steel pipe, the difference between the seamless steel pipe and the welded steel pipe is that there are welding ribs on the inner wall of the welded pipe, while the seamless one does not.
Identification method: look at the inside of the pipe, because the outside will be treated. The welded pipe has a gap in it, some can be seen, and some are treated, it is not easy to see, you can touch it slowly with your hand, or look at the specifications, the welded pipe is not easy to see. Relatively thin, seamless steel pipe manufacturers, welded pipes are made directly from stainless steel strips (rolled up) by machines, and seamless are pierced with round steel or tube blanks.
The production principle of seamless steel pipe
The production method can be divided into hot-rolled pipe, Soğuk haddelenmiş boru, Soğuk çekilmiş boru, ekstrüde edilmiş boru, vb. Farklı üretim yöntemlerine göre. Sıcak haddelenmiş dikişsiz boru, genellikle otomatik haddeleme ile üretilmektedir. After inspection and removal of surface defects, the solid tube blank is cut into required lengths, Boş borunun delikli ucunun alın yüzeyi üzerinde merkezlenmiş, then sent to a heating furnace for heating, and perforated on a punching machine. During the continuous rotation and advancement of the perforation at the same time, under the action of the roll and the plug, bir boşluk yavaş yavaş boru boş içinde oluşturulmuştur, which is called a capillary. And then sent to the automatic rolling mill to continue rolling. The wall thickness of the whole machine is averaged, the diameter is sizing by the sizing machine, and the picture of the 20# seamless steel pipe meets the specification requirements.
1. Different outer surfaces
It can be seen from the outer surface of the seamless steel pipe that there is no gap on the whole; the welded steel pipe has a welding gap.
2. Different molding processes
The seamless steel pipe is perforated by the whole round steel, and the steel pipe without weld on the surface is called seamless steel pipe.
Welded steel pipes are steel pipes made by crimping and welding steel plates or steel strips. uzunluğu genel olarak 6 metre, and there are welds on the surface. The production process of welded steel pipe is simple, the production efficiency is high, the variety and specifications are many, and the equipment investment is low, but the general strength is lower than that of seamless steel pipe.
3. Different categories
Dikişsiz çelik boru: According to the different production methods, Sıcak haddelenmiş boru ayrılmıştır, Soğuk haddelenmiş boru, Soğuk çekilmiş boru, ekstrüde edilmiş boru, boru krikosu, vb., hepsinin kendi süreç düzenlemeleri vardır.
Dikişli boru: divided into general welded pipe, galvanized welded pipe, oxygen blown welded pipe, wire shell, metric welded pipe, roller pipe, deep well pump pipe, automobile pipe, transformer pipe, electric welding thin-walled pipe, electric welding special-shaped pipe, scaffolding pipe and spiral welded pipe.
4. Different physical properties
Seamless steel pipe is often used in high pressure equipment because it has better bearing capacity than ordinary steel pipe. Such as hydraulic equipment, boru hattı connections, vb. The welding position of ordinary steel pipe is the weak link, and the quality of the weld is the main factor affecting its comprehensive performance. The physical properties of seamless steel pipe are better than that of welded steel pipe, and the compressive performance is higher. Welded pipes are generally around 10mpa. Now welded pipes can be processed seamlessly.
5. Different prices
The price of seamless steel pipe is generally higher than that of welded steel pipe.
6. Different uses
The factory generally uses seamless steel pipes; welded steel pipes are generally used in construction.
The application of seamless steel pipe is very extensive. Universal seamless steel pipe is rolled from ordinary carbon structural steel, Düşük alaşımlı çelik konstrüksiyon veya alaşımlı çelik konstrüksiyon, ve en büyük çıkışı. Mainly used for pipelines or structural parts for transporting fluids, such as petroleum geological drilling pipes, petrochemical cracking pipes, vb. Steel pipes for automobiles, traktörler, Havacılık, kazan boruları, bearing pipes and high-precision structural steel pipes.
Welded pipes are widely used in water supply engineering, Petrokimya, kimyasal, elektrik gücü, tarımsal sulama, urban construction and other fields.
Welded pipes are used for liquid conveying: su temini ve drenaj. For natural gas transportation: gaz, buhar, sıvılaştırılmış petrol gazı; structural use: used for pile pipes, köprüler, piers, yollar, building structures, vb.
1. Size and allowable deviation:
Deviation grade D1: Standardized outer diameter tolerance ±1.5%, minimum ±0.75 mm
Deviation grade D2: Standardized outer diameter tolerance ±1.0%. Min ±0.50 mm
Deviation grade D3: Standardized outer diameter tolerance ±0.75%. Minimum ±0.30 mm
Deviation grade D4: Standardized outer diameter tolerance ±0.50%. Minimum ±0.10 mm
2. The national standard seamless steel pipe is made of steel ingots or solid tube blanks through perforation to make capillaries, ve sonra sıcak haddelenmiş, soğuk haddelenmiş veya soğuk çekilmiş.
3. The national standard seamless steel pipe is made of steel ingots or solid tube blanks through perforation to make capillaries, ve sonra sıcak haddelenmiş, soğuk haddelenmiş veya soğuk çekilmiş. National standard steel pipes have an important position in my country’s steel pipe industry. Eksik istatistiklere göre, dan daha fazla var 240 national standard steel pipe manufacturers in my country, daha fazla 250 sets of seamless steel pipe units, and an annual production capacity of about 4.5 milyon ton.
4. sınıflandırma: Seamless steel pipes are divided into two categories: hot-rolled and cold-rolled (dial) dikişsiz çelik borular.
(1) Hot-rolled seamless steel pipes are divided into general steel pipes, Düşük ve orta basınçlı kazan çelik borular, Yüksek basınçlı kazan çelik borular, alaşımlı çelik borular, paslanmaz çelik borular, Petrol çatlama boruları, Jeolojik çelik boru ve diğer çelik borular.
(2) In addition to general steel pipes, Düşük ve orta basınçlı kazan çelik borular, Yüksek basınçlı kazan çelik borular, alaşımlı çelik borular, paslanmaz çelik borular, Petrol çatlama boruları, and other steel pipes, cold-rolled (dial) seamless steel pipes also include carbon thin-walled steel pipes and alloy thin-walled steel pipes. Wall steel pipe, stainless thin-walled steel pipe, special-shaped steel pipe. Sıcak haddelenmiş dikişsiz borunun dış çapı genellikle 32 mm'den büyüktür., and the wall thickness is 2.5-75mm. The diameter of the cold-rolled seamless pipe can reach 6mm and the wall thickness can reach 0.25mm. Cold rolling has higher dimensional accuracy than hot rolling.
5. The formula for calculating the pressure of the national standard seamless steel pipe:
(1) The calculation method of the outer diameter, specification and wall thickness of the national standard seamless pipe can withstand the pressure (the tensile strength of different materials of the steel pipe is different) Pressure = (duvar kalınlığı * 2 * tensile strength of the steel pipe material) / (Dış çap * coefficient)
(2) The calculation method of the known seamless steel pipe outer diameter and pressure bearing wall thickness: Wall thickness = (basınç * Dış çap * coefficient) / (2 * tensile strength of steel pipe material)
(3) Representation method of seamless pipe pressure coefficient: steel pipe pressure P17.5 coefficient S=4