Production & Stock Range of Stainless Steel Seamless Pipes

Types of Stainless Steel Seamless Pipes

Austenitic Stainless Steel Seamless Pipes

• Austenite refers to stainless steel containing chromium 18% above, nickel 8% around, as well as a small amount of molybdenum, titanium, nitrogen and other elements. The large amount of Ni and Cr contained within makes the steel structure austenitic under room temperature.
• Austenitic stainless steel seamless pipes feature good overall performance: good plasticity, toughness, weldability, corrosion resistance and non-magnetic properties. Its good corrosion resistance manifests itself in both oxidizing and reducing media. Hence, it is applied to make acid-resistant equipment such as corrosion-resistant containers, equipment lining , pipelines, and equipment parts resistant to nitric acid, etc.. In addition, it is used for stainless steel watches and clocks as the main material.
• If you want to buy austenitic stainless steel seamless pipes, please contact Metallica to get the latest price.

Duplex Stainless Steel Seamless Pipes

• Austenitic – ferritic duplex stainless steel embodies the features of both austenitic and ferritic stainless steels, with ferrite accounting for 50% and austenite approximately or at least 30%. It is also a nickel-saving stainless steel. In the case of low carbon content, the Cr content is 18% to 28%, and the Ni content is 3% to 10%. Some duplex also contains alloying elements such as Mo, Cu, Nb, Ti, and N. The commonly used duplex grades are S31803, 2205, and 2507.
• Duplex stainless steel seamless pipe feature excellent pitting corrosion resistance and super plasticity. Compared with ferrite, it features better toughness, plasticity, intergranular corrosion resistance, weldability, and iron retention.
• Duplex stainless steel seamless pipes maintain the brittleness at 475°C and high thermal conductivity like Ferrite, yet it is free from room temperature brittleness.
• In comparison with Austenitic stainless steel seamless pipes, it features high strength and excellent resistance to intergranular corrosion and chloride stress corrosion.

Precipitation Hardening (PH) Stainless Steel Seamless Pipes

• Precipitation hardening stainless steel seamless pipes are famous for their dual properties, i.e. 1) the high strength and hardness of Martensitic stainless steel and 2) good corrosion resistance of Austenitic stainless steel. Martensitic PH steels, for example, present a predominantly austenitic structure at annealing temperatures 1040 – 1065°C. When cooling to room temperature, they undergo a transformation that alters the austenite to martensite.
• The high tensile strengths of precipitation hardening stainless steel seamless pipes is a result of heat treatment process that leads to precipitation hardening of a martensitic or austenitic matrix, while hardening is achieved through the addition of one or more of the elements Copper, Aluminium, Titanium, Niobium, and Molybdenum. All precipitation hardening stainless steel contains a relatively high chromium content.
• There are Austenitic, Semi-austenitic and Martensitic precipitation hardening stainless steels, represented by A-286, 17-7PH, 17-4PH respectively. Most applications of precipitation hardening stainless steel pipes are for corrosion resistance or oxidation resistance and retention of strength at elevated temperatures.

Ferritic Stainless Steel Seamless Pipes

• Ferritic steels are high chromium (10.5% – 27%), magnetic stainless steels with a low carbon content and little to no nickel content. With the increase of chromium content, its corrosion resistance, toughness and weldability improve correspondently. Its resistance to chloride stress corrosion is superior to other types of stainless steel. The common ferritic grades are Crl7, Cr17Mo2Ti, Cr25, Cr25Mo3Ti, Cr28 and the like.
• Ferritic stainless steel seamless pipes feature high corrosion resistance and oxidation resistance due to its high chromium content, but its mechanical properties and machinability are poor. It is widely applied to acid-resistant structures with little stress and is used as anti-oxidation steel.
• This steel type can resist the corrosion of atmospheric, nitric acid and saline solution. It features high temperature oxidation resistance and small thermal expansion coefficient. It can be used in nitric acid and food factory equipment, and can also be used to produce parts working at high temperature, such as gas turbine parts.

Martensitic Stainless Steel Seamless Pipes

• Martensitic stainless steels are built around grade 410 composition of iron, 12% chromium, and up to 1.2% carbon. Like Ferritic stainless steel, it contains little to no nickel content. The typical martensitic grades are 1Cr13, 3Cr13, etc.. They can be high- or low-carbon steels, hardenable through heat treatment, specifically by quenching, or by quenching and tempering.
• Martensitic stainless steel pipes feature high strength, but poor plasticity and weldability. Due to the high carbon content, Martensitic stainless steel features high strength, hardness and wear resistance. Since its corrosion resistance is slightly poor, it is generally used to those parts that have special requirements on mechanical properties but relatively low requirements on corrosion resistance, such as springs, steam turbine blades, hydraulic press valves, etc. This type of steel is generally used after quenching and tempering.

Chemical Composition Of Seamless Stainless Steel Pipe

Difference Between Seamless and Welded Stainless Steel Pipe. How to Identify Whether a Pipe is Seamless or Welded?

Electric Resistance Welding (ERW) pipe is manufactured by rolling metal and then welding it longitudinally across its length. Seamless pipe is manufactured by extruding the metal to the desired length; therefore ERW pipe have a welded joint in its cross-section, while seamless pipe does not have any joint in its cross-section through-out its length.

In Seamless pipe, there are no welding or joints and is manufactured from solid round billets. The seamless pipe is finished to dimensional and wall thickness specifications in sizes from 1/8 inch to 26 inch OD. Applicable in for High-pressure applications such as Hydrocarbon Industries & Refineries, Oil & Gas Exploration & Drilling, Oil & Gas Transportation and Air and Hydraulic cylinders, Bearings, Boilers, Automobiles, etc.

ERW (Electric Resistance Welded) pipes are welded longitudinally, manufactured from Strip / Coil and can be manufactured upto 24” OD. ERW pipe cold formed from a ribbon of steel pulled through a series of rollers and formed into a tube which is fused through a electric charge. It is mainly used for low/ medium pressure applications such as transportation of water / oil. Common sizes for ERW Steel Pipe range from 2 3/8 inch OD to 24 inch OD in a variety of lengths to over 100 feet. Surface finishes are available in bare and coated formats and processing can be handled on site to customer specifications.

How to identify whether the pipe is seamless or welded?

If it is ASTM A53,

Type S means seamless.
Type F is furnace but welded,
Type E is Electrical resist welded.
That is how. It is the easiest way to identify whether pipe is Seamless or ERW.

Manufacturing Process of Seamless Stainless Steel Pipe

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Seamless Pipes Manufacturing Process:

1. Mandrel Mill Process
2. Mannesmann Plug Mill Pipe Manufacturing Process
3. Forged Seamless Pipe Manufacturing Process
4. Extrusion Processes

They are explained below:-

1. Mandrel Mill Process: – In the Mandrel Mill Process, a solid round (billet) is used. It is heated in a rotary hearth heating furnace and then pierced by a piercer. The pierced billet or hollow shell is rolled by a mandrel mill to reduce the outside diameter and wall thickness which forms a multiple length mother tube. The mother tube is reheated and further reduced to specified dimensions by the stretch reducer. The tube is then cooled, cut, straightened and subjected to finishing and inspection processes before shipment.
2. Mannesmann Plug Mill Process: – In the Plug Mill Process, a solid round (billet) is used. It is uniformly heated in the rotary hearth heating furnace and then pierced by a Mannesmann piercer. The pierced billet or hollow shell is roll reduced in outside diameter and wall thickness. The rolled tube simultaneously burnished inside and outside by a reeling machine. The reeled tube is then sized by a sizing mill to the specified dimensions. From this step the tube goes through the straightener. This process completes the hot working of the tube. The tube (referred to as a mother tube) after finishing and inspection, becomes a finished product.
3. Forged Seamless Pipe Manufacturing Process: – Steel Products may be manufactured either by casting or forging steel. Forged Seamless Pipe Manufacturing Process implies the application of mechanical forces to heated solid blocks of steel (such as ingots and/or billets) that are shaped into desired products permanently. They require the application of high temperatures to steel raw materials (to liquefy or make it malleable).Once this forging is done, pipe is machined to achieve final dimension. Forged pipes are generally used for the steam header. This process is used to manufacture large diameter seamless pipe that cannot be manufactured using traditional methods.
4. Extrusion Processes: – Metal extrusion is a metal forming process in which a work piece, of a certain length and cross section, is forced to flow through a die of a smaller cross sectional area, thus forming the work to the new cross section. The length of the extruded part will vary, dependent upon the amount of material in the work piece and the profile extruded. Numerous cross sections are manufactured by this method. The cross section produced will be uniform over the entire length of the metal extrusion. Starting work is usually a round billet, which may be formed into a round part of smaller diameter, a hollow tube, or some other profile.  Metal extrusion is a forming process, like other metal forming processes; it can be performed either hot or cold.

Various Grades of Stainless Steel, Metallica Deals in

As one of the biggest stainless steel suppliers in India, we stock and supply all major grades of stainless steel.

Impact of Various Alloying Elements on the Properties of Stainless Steel

Steel Pipe Sizes

Pipe size is quoted as a “Nominal Pipe Size” or NPS. The origin of the NPS numbers for smaller pipes (< NPS 12) is different to the origin for larger diameter pipes. However, all pipes of a specific NPS number have the same external or outer diameter (OD). The internal diameter will vary depending on the wall thickness of the metal. The reason for this is so that the same structural supports can be used for all piping of a specific NPS number regardless of the wall thickness.

Schedules

Steel pipe schedules are a way to describe the wall thickness of the pipe. This is a critical parameter as it is directly related to the strength of the pipe and the suitability for specific applications. A pipe schedule is a dimensionless number and is calculated based on the design formula for wall thickness, given the design pressure and allowable stress.

Examples of schedule numbers are as follows: 5, 5S, 10, 20, 30, 40, 50, 60, 80, 100, 120, 140, 160, STD, XS, and XXS—with the most common being schedules 40 and 80. As the schedule number increases, the wall thickness of the pipe increases. The schedule number of a pipe therefore defines the internal diameter, as the OD is fixed by the NPS number.

Over 1000 Tons in Stock for Stainless Steel Pipes! ISMT & Jindal Steel Pipes Dealers, Original MTR’s Provided with All Materials

As one of the biggest stainless steel pipe stockholder and supplier in India, Metallica carries inventory of over 1,000 tons in its warehouses in Mumbai, Maharashtra India. We sell our stainless steel pipe products throughout India, and to international clients. We can supply our stainless steel tube products not only in industry-standard lengths and diameters, but also in custom length and diameters.

Certification of Steel Pipes

Manufacturers issue a Material Test Report or Mill Test Report to validate that the product meets the chemical analysis and mechanical properties specification. The MTR will contain all relevant data to the product and will accompany the product through its lifecycle.

The following are typical parameters that may be recorded on an MTR:

• Chemical composition including carbon content, alloys, and sulfur
• Material size, weight, identification, and grade
• Material heat number, which ties back to the processing batch
• Mechanical properties like tensile strength, yield strength, and elongation

At Metallica, we will Provide you with Original MTR’s for all Stainless Steel Pipe Products! We will Send Our Test Certificates, along with Quotation

Maximum Operating Temperatures of Stainless Steel Grades

Stainless steels have good strength and good resistance to corrosion and oxidation at elevated temperatures. Stainless steels are used at temperatures up to 1700° F for 304 and 316 and up to 2000 F for the high temperature stainless grade 309(S) and up to 2100° F for 310(S).

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