What is stainless steel pipe/stainless steel tube？

stainless steel pipe/stainless steel tube

A. Classification by production method:

(1) Seamless pipes – cold drawn pipes, extruded pipes, cold rolled pipes. Manufacturing process: Smelting>Ingot>Rolling>Sawing>Peeling>Piercing>Annealing>

Pickling>Ash application>Cold drawing>Cutting>Pickling>Storage

The characteristics of seamless steel pipes: It is not difficult to see from the above process flow: firstly, the thicker the wall thickness of the product, the more economical it is

The thinner the wall thickness, the greater its practicality and practicality, the higher its processing cost will be; Secondly, the process of the product determines its limited performance,

General seamless steel pipes have low accuracy: uneven wall thickness, low surface brightness inside and outside the pipe, high sizing cost, and difficult to spot and black spots on the inner and outer surfaces

remove; Thirdly, its detection and shaping must be processed offline. Therefore, it embodies its advantages in high pressure, high strength, and mechanical structural materials

Superiority.

Manufacturing of seamless steel pipes: Seamless steel pipes are made from steel ingots or solid billets that are perforated into tubes, and then hot rolled, cold rolled, or cold drawn.

The specifications of seamless steel pipes are expressed in millimeters of outer diameter * wall thickness. Seamless steel pipes are divided into two categories: hot-rolled and cold-rolled (drawn) seamless steel pipes. Hot rolled seamless pipe outer

The diameter is generally greater than 32mm, with a wall thickness of 2.5-75mm. The diameter of cold-rolled seamless steel pipes can reach 6mm, and the wall thickness can reach 0.25mm. The outer diameter of thin-walled pipes

It can reach a wall thickness of 5mm and less than 0.25mm, with higher dimensional accuracy in cold rolling compared to hot rolling. Hot rolled steel pipes are delivered in hot rolled or heat treated condition; cold rolling

Delivered in heat treated condition.

1. Hot rolling (extruded seamless steel pipe): Round tube billet → Heating → Piercing → Three roll oblique rolling, continuous rolling or extrusion → Tube detachment → Sizing

(or reducing) → cooling → straightening → hydraulic test (or flaw detection) → marking → warehousing

2. Cold drawn (rolled) seamless steel pipe: round tube blank → heating → perforation → heading → annealing → acid pickling → oil coating (copper plating) → multiple

Pass cold drawing (cold rolling) → blank tube → heat treatment → straightening → water pressure test (flaw detection) → marking → storage

(2) Welded pipe: Welded steel pipe, abbreviated as welded pipe, is a steel pipe made by welding steel plates or strips after being rolled and formed by a machine and a mold.

1. Steel plate>Splitting>Forming>Fusion welding>Induction bright heat treatment>Inner and outer weld bead treatment>Shaping>Sizing>Eddy current testing>Laser diameter measurement>

Pickling>Storage.

The characteristics of welded steel pipes: It is not difficult to see from the above process flow: firstly, the product is continuously produced online, with thicker walls,

The larger the investment in the unit and fusion equipment, the less economical and practical it will be. The thinner the wall thickness, the corresponding decrease in its input-output ratio

Descending; Secondly, the process of this product determines its advantages and disadvantages. Generally, the welded steel pipe has high precision, uniform wall thickness, and high surface brightness inside and outside the pipe (steel plate

The surface level of the steel pipe determines the surface brightness, and can be arbitrarily sized. Therefore, it embodies its advantages in high-precision, medium and low pressure fluid applications

Economy and aesthetics.

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

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

b: Classified by cross-sectional shape: circular tube, square tube, rectangular tube, elliptical tube

(1) Simple cross-section steel pipes – circular steel pipes, square steel pipes, elliptical steel pipes, triangular steel pipes, hexagonal steel pipes, diamond steel pipes, eight

Angular steel pipes, semi-circular steel circles, others

(2) Complex cross-section steel pipes – unequal hexagonal steel pipes, five petal plum shaped steel pipes, double convex steel pipes, double concave steel pipes, melon shaped steel pipes

Conical steel pipes, corrugated steel pipes, watch case steel pipes, others

c: Classification by wall thickness: thin-walled steel pipes:

Thick walled steel pipe:

d: Classified by purpose: (1) Civil pipes are divided into circular pipes, rectangular pipes, and flower pipes, which are generally used for decoration, architecture, structure, and other aspects;

(2) Industrial pipes: steel pipes for industrial piping, steel pipes for general piping (drinking water pipes), mechanical structures/fluid delivery pipes

Boiler heat exchange pipes, food hygiene pipes, etc. Generally applied in various fields of industry, such as petrochemical, papermaking, nuclear energy, food, beverage

The pharmaceutical and other industries have high requirements for fluid media in pipelines.

e: Market quotation types for stainless steel pipes: pipe blanks, welded pipes, industrial pipes, and sanitary pipes

From the perspective of process flow, the differences between the steel pipes classified above are:

1. Hygienic grade mirror tube process flow:

Tube blank – inspection – peeling – inspection – heating – perforation – acid cleaning – grinding – lubrication and air drying – welding head——

Cold drawing – solid solution treatment – pickling – pickling passivation – inspection – cold rolling – degreasing – cutting – air drying – internal polishing

——External polishing – Inspection – Identification – Finished product packaging

Sanitary (food grade) seamless stainless steel pipe is widely used in pharmaceutical, food, beer, drinking water, biological engineering, chemical engineering, air purification

Aviation, nuclear industry and other national economic construction are widely used in many fields and industries. Sanitary grade stainless steel pipes for general industrial use Ф 14*1mm

to Ф 200*3mm。 Waste management: Ф 65 * 5 to Ф 100*7

2. Industrial Pipe Process Flow

Tube blank – inspection – peeling – inspection – heating – perforation – acid cleaning – grinding – lubrication and air drying – welding head——

Cold drawing – solid solution treatment – pickling – pickling passivation – inspection

3. Welding pipe process flow:

Unwinding – leveling – end shearing and welding – looper – forming – welding – removal of inner and outer weld beads – pre calibration——

Induction heat treatment – Sizing and straightening – Eddy current testing – Cutting – Hydraulic inspection – Pickling – Final inspection – Packaging

f: According to the main material composition types: 304, 304L, 316, 316L, 301S, 321, 309S, 2205, 17-4PH, Ni10Ti

(Note: The meaning of adding TP before the steel pipe model is TP – precipitation hardening treatment)

2205 alloy (UNS S32305/S31803) is a duplex stainless steel composed of 22% chromium, 3% molybdenum, and 5-6% nickel nitrogen alloy. It has

High strength, good impact toughness, and good overall and local resistance to synergistic corrosion.

Compared with 316L and 317L austenitic stainless steel, 2205 alloy has superior performance in corrosion resistance and crack resistance. It has

High corrosion resistance. Compared with austenite, it has lower coefficient of thermal expansion and higher thermal conductivity.

Compared with austenitic stainless steel, its compressive strength is twice that of 316L and 317L, and designers can reduce its weight by

The cost is also lower.

17-4PH (C: 0.04, Cr: 16.5, Ni: 4.5, Cu: 3.3, Mn: 0.7) alloy is stainless for precipitation, quenching and martensite

Steel, with this grade, has characteristics such as high strength, hardness (up to 3000 C/5000 C), and corrosion resistance. After heat treatment, the product’s

The mechanical properties are more complete, and can reach a compressive strength of up to 1100-1300 mpa (160-190 ksi). This level cannot be used above

At temperatures of 300 0C (572 0F) or very low, it has good corrosion resistance to the atmosphere and diluted acids or salts, and its corrosion resistance

The force is the same as 304 and 430.

Ni10Ti 321 constitutes 0Cr18Ni10Ti