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Stainless steel decorative pipe

Stainless steel decorative pipe

Time:2022-04-07 Source:Wuxi Jianuo Special Steel Co.

Stainless steel decorative pipe is also called stainless steel welded steel pipe or welded pipe, commonly used steel or steel strip after the unit and mold curl forming welded steel pipe. Welded steel pipe production process is simple, high production efficiency, a variety of specifications, less equipment capital, but the general strength is lower than seamless steel pipe.


Equipment introduction

Since the 1930s, with the rapid development of continuous rolling production of high-quality strip steel and the progress of welding and inspection technology, the quality of the welded seam continues to improve, the increasing variety of welded steel pipe specifications, and in more and more areas, especially in the heat transfer equipment, decorative tubes, low and medium pressure fluid tubes instead of seamless steel tubes.


There are many kinds of stainless steel tubes, but the main ones have the following uses.

A, the classification of stainless steel pipe

1, according to the production method classification.

(1) seamless tube – cold-drawn tube, extruded tube, cold-rolled tube.

(2) Welded tubes.

(a) Classification by process – gas shielded welded pipe, electric arc welded pipe, resistance welded pipe (high frequency, low frequency).

(b) by welding seam – straight seam welded pipe, spiral welded pipe.

2, classified by section shape: (1) round steel pipe; (2) rectangular pipe.

3, according to the classification of wall thickness – thin-walled steel pipe, thick-walled steel pipe

4, according to the classification of use: (1) civil tube into round, rectangular, flower tube, generally used for decoration, construction, structure, etc..

(2) industrial pipe: industrial piping with steel pipe, general piping with steel pipe (drinking water pipe), mechanical construction / fluid transfer tube, boiler heat exchange tube, food sanitation tube, etc.. Generally used in various fields of industry such as: petrochemical, paper, nuclear energy, food, beverage, pharmaceutical and other industries with high requirements for fluid media pipeline.

Second, seamless steel pipe

Stainless steel seamless tube is a long steel with hollow cross-section and no seams around.

1. Manufacturing process and process of seamless steel pipe.

Smelting > ingot > rolling > sawing > peeling > perforation > annealing > pickling > ashing > cold drawing > head cutting > pickling > storage

2. The characteristics of seamless steel pipe:

From the above process we can easily see: first, the thicker the wall thickness of the product, the more economical and practical it is, the thinner the wall thickness, its processing costs will rise significantly; second, the product’s process determines its limitations, the general seamless steel pipe low precision: uneven wall thickness, low brightness of the tube’s inner appearance, high cost of sizing, and the inner and outer surfaces and pockmarks, black spots are not easy to remove; third, its Detection and shaping must be processed off-line. Therefore, it reflects its superiority in high pressure, high strength, mechanical structural materials.

Third, welded steel pipe

304 stainless steel decorative tube

Welded steel pipe, referred to as welded pipe, is a stainless steel pipe made of steel plate or steel strip after the unit and mold curling and forming and welding.

1. steel plate > slitting > forming > dissolving > induction bright heat treatment > internal and external welding channel treatment > shaping > sizing > eddy current detection > laser diameter measurement > pickling > storage

2. Characteristics of welded steel pipe:

From the above process flow we can easily see: one, the product is continuous online production, the thicker the wall thickness, the larger the investment in units and dissolving equipment, the less economical and practical it is. The thinner the wall thickness, its input-output ratio will drop accordingly; secondly, the process of the product determines its advantages and disadvantages, general welded steel pipe with high precision, uniform wall thickness, stainless steel pipe fittings with high brightness of the inner appearance (steel surface grade of the steel pipe surface brightness), can be arbitrarily sized. Therefore, it embodies its economy and beauty in high-precision, low and medium pressure fluid applications.

Rusting reason edit Podcast

The presence of chloride ions in the use environment. Chlorine ions are widely present, such as salt, sweat stains, seawater, sea breeze, soil, etc. Stainless steel in the presence of chloride ions in the environment, corrosion is rapid, even more than ordinary low carbon steel. So there are requirements for the use environment of stainless steel, and it needs to be wiped frequently to remove dust and keep it clean and dry.

316 and 317 stainless steel (317 stainless steel properties see later) is a molybdenum-containing stainless steel. 317 stainless steel has a slightly higher molybdenum content than 316 stainless steel. Due to the molybdenum in the steel, the total performance of the steel is better than 310 and 304 stainless steel, high temperature conditions, when the concentration of sulfuric acid is less than 15% and higher than 85%, 316 stainless steel has a wide range of uses. 316 stainless steel also has good and chloride erosion performance, so it is usually used in the marine environment. Stainless steel pipe with the development of social and economic development, its application has also been more and more widely popular. Will certainly bring a new change in various fields.

Seamless pipe production

a. Round steel preparation.


c. Hot-rolled perforation; c. Hot-rolled perforation

d. Cutting head

e. Pickling.


Welded pipe process

a Plate and strip preparation

b Slitting

c Forming

d Welding

e Cutting

f Grinding

g Polishing

Calculation formula

304 stainless steel pipe is the most widely used as stainless heat-resistant steel, equipment for food, general chemical equipment, equipment for the atomic energy industry. 304 stainless steel pipe is a general-purpose stainless steel pipe, which is widely used to make equipment and machine parts that require good overall performance (corrosion resistance and formability). 304 stainless steel pipe is the most widely used stainless steel, heat-resistant steel. Used in food production equipment, xietong chemical equipment, nuclear energy, etc.

304 stainless steel pipe chemical composition Specifications C Si Mn P S Cr Ni (nickel) Mo SUS304 ≤0.08 ≤1.00 ≤2.00 ≤0.05 ≤0.03 18.00-20.00 8.25~10.50 – 304 stainless steel is a general-purpose stainless steel material, rust resistance than the 200 series of stainless steel materials. 304 stainless steel has excellent stainless corrosion resistance and good resistance to intergranular corrosion. 304 stainless steel material concentration ≤ 65% of the boiling temperature below the nitric acid, has a very strong resistance to corrosion. To alkali solutions and most organic and inorganic acids also have good corrosion resistance. In the air or chemically corrosive media to resist corrosion of a high-alloy steel, stainless steel is a beautiful surface and good corrosion resistance, without the need for surface treatment such as color plating, and play the inherent surface properties of stainless steel, used in many aspects of a kind of steel, usually called stainless steel. The representative performance of 13 chromium steel, 18-8 chromium-nickel steel and other high-alloy steel. From the metallographic point of view, because the stainless steel contains chromium and the surface of the formation of a very thin chromium film, this film separates the invasion of oxygen with the steel to play a role in corrosion resistance. In order to maintain the inherent corrosion resistance of stainless steel, the steel must contain more than 12% chromium.

Stainless steel pipe weight formula: [(outside diameter – wall thickness) * wall thickness] * 0.02491 = kg/m (the weight of each meter) kg

Size and Deviation

Deviation grade

Standardized outside diameter allowable deviation


±1.5%, minimum ±0.75 mm


±1.0%. Min ±0.50 mm


±0.75%. Min ±0.30 mm


±0.50%. Min ±0.10 mm

Production Process Editor Podcast

a. Round steel preparation; b. Heating; c. Hot rolling and piercing; d. Cutting head; e. Pickling; f. Finishing Stainless steel welded decorative pipe production process a plate and strip preparation b slitting c forming d welding e cutting f finishing g polishing

Connection Edit Podcast

Stainless steel pipes are connected in various ways: common types of fittings are compression, compression, live connection, push, push thread, socket welding, live flange connection, welding and welding combined with the traditional connection of the derivative series of connections. The scope of application of these connections varies according to their principles, but most of them are easy to install, solid and reliable. Most of the sealing ring or gasket materials used for the connection are silicon rubber, nitrile rubber and EPDM rubber, which meet the requirements of national standards and eliminate the worries of users.