Boiler Superheaters and Reheater Sections
Superheater and reheater sections hold pressure while hot for the length of every run. 321H is drawn to the element list for these circuits because its carbon window and lot grain size answer that duty.
ASTM A213 / ASME SA-213 / UNS S32109 / W.Nr. 1.4878
Stainless Steel 321H Seamless Tubes Manufacturer in Thailand
Heat-resisting ASTM A213 TP321H stainless steel seamless tubes come from the Ban Bueng, Chonburi mill of Thaida Stainless Steel Manufacturing (Thailand) Co., Ltd. in Thailand, sized for superheater, reheater and refinery heater circuits where creep sets the wall. The grade is UNS S32109, cross-referenced to WNR 1.4878, and it joins the stabilized H types inside our stainless steel seamless tubes range. The test records and order papers are issued at our Bang Phli, Samut Prakan office.
Stainless Steel 321H seamless tubeUNS S32109 / W.Nr. 1.4878
- 6.35 to 257 mmOutside diameter
- 0.89 to 12.7 mmWall thickness
- Up to 22 mLength
EN 10204 3.1 certificate / 3.2 on request
Specification Sheet for ASTM A213 TP321H Stainless Steel Seamless Tubes
Two figures govern each item on a 321H order: the outside diameter and the wall. An H grade adds a grain size reading and a heat-treatment lot reference, so name the wall basis against each diameter.
- Specification
- ASTM A213, grade TP321H; ASME SA-213 where code work applies
- Grade Numbers
- UNS S32109WNR 1.4878 quoted only as a cross-reference
- Outside Diameter
- 6.35 to 257 mm
- Wall
- 0.89 to 12.7 mmminimum wall unless average wall is named
- Length
- Up to 22 m straight, or cut to the lengths on your element list
- Finishing Route
- 1Seamless throughout
- 2Finished hot or finished cold
- Solution Treatment
- Cold worked from 1090 °C (2000 °F); hot rolled from 1050 °C (1925 °F); cooled in water or as rapidly by other means
- Carbon Window
- 0.04 to 0.10%
- Grain Size
- No. 7 or coarser on the ASTM E112 scale
- Outer Surface
- Pickled clear of scaleor bright annealed and left unpickled
- Per-Tube Proof
- Hydrostatic pressure test, or a nondestructive electric examination in its place
- Per-Lot Tests
- Tension, hardness, flattening, flaring, grain size
- Per-Heat Test
- Product analysis on one billet or one tube from the heat
- Document
- EN 10204 3.13.2 on request
A213 is written for seamless tubing that goes into boilers, superheaters and heat exchangers, and it treats the H grades separately: the extra rules they carry raise creep-rupture strength above what the same composition reaches without them. On a TP321H item those extra rules are the carbon window, the two solution temperatures and the limit on grain size; ASME SA-213 takes all three unchanged into code work. Where a drawing gives a nominal bore and a schedule instead of a diameter and a wall, the same grade is produced as stainless steel 321H seamless pipes.
Release testing starts at the heat: A213 has one billet or one tube analyzed from every heat, which puts the carbon window on the product record and not only on the melt record. Each finished tube is then proved individually: either a hydrostatic pressure test or a nondestructive electric examination, our choice unless your order fixes it. Lot work follows. Tension is tested on one tube per lot up to 50 pieces and on two tubes once the lot runs larger; two tubes from the lot supply the hardness specimens; flattening is tested at the two ends of one finished tube and flaring at the two ends of a different one; and the grain size is read. Results are collected into an EN 10204 3.1 (3.2 on request) certificate, and an independent inspection body can witness the work where your order asks for it.
Heat Analysis Limits for UNS S32109 Seamless Tube
A213 fixes the composition of a UNS S32109 seamless tube as set out below, in weight percent. Both the heat analysis and the later product analysis are judged against it, and a figure standing on its own is a maximum.
- CrChromium, 17.0 to 19.0
- NiNickel, 9.0 to 12.0
- TiTitanium, 4 × (C + N) min, 0.70 max
- MnManganese, 2.00 max
- SiSilicon, 1.00 max
UNS S32109321H
| Element | A213 Limit for TP321H, % |
|---|---|
| C (Carbon) | 0.04 to 0.10 |
| Mn (Manganese) | 2.00 max |
| P (Phosphorus) | 0.045 max |
| S (Sulfur) | 0.030 max |
| Si (Silicon) | 1.00 max |
| Cr (Chromium) | 17.0 to 19.0 |
| Ni (Nickel) | 9.0 to 12.0 |
| Ti (Titanium) | 4 × (C + N) min, 0.70 max |
Titanium is written as a ratio rather than a band: four times the combined carbon and nitrogen as the floor, 0.70% as the ceiling. Nitrogen carries no limit at all in A213 for this grade, so the floor follows the analyzed figures printed on your certificate. Because titanium takes carbon ahead of chromium, chromium stays in solution instead of forming carbide at the grain boundaries while the tube is welded and while it runs hot.
Strength and Hardness of SS 321H Seamless Tube
Each lot is tension tested after solution treatment and read against the single set of minimums A213 gives TP321H.
| Property | Requirement, TP321H |
|---|---|
| Tensile strength, min | 515 MPa (75 ksi) |
| Yield strength, min | 205 MPa (30 ksi) |
| Elongation in 50 mm (2 in.), min | 35% |
| Hardness, max | 192 HBW / 200 HV, or 90 HRB |
There is no wall-thickness step in these figures. A 12.7 mm wall is judged against the same 515 MPa and 205 MPa as a 0.89 mm wall, so a heavy element and a thin one carry the same strength floor. Two tubes from each lot supply the hardness specimens: walls of 5.1 mm and over may be read by Brinell, Rockwell or Vickers, walls from 1.65 mm up to 5.1 mm by Rockwell or Vickers, and walls under 1.65 mm need no hardness reading at all.
Solution Treatment and Grain Size of Seamless 321H Tube
How the tube was finished decides the solution temperature. Cold worked tube is treated from 1090 °C (2000 °F) upward, hot rolled tube from 1050 °C (1925 °F) upward, and either is cooled in water or as rapidly by other means. A213 also lets the tube be quenched straight after hot forming, with no separate reheat, provided it has not dropped below the minimum for its route.
The grain size entered against a lot of seamless S32109 stainless steel tube then has to read No. 7 or coarser. The specimen comes from one end of a single finished tube out of each lot and is assessed by the ASTM E112 methods, so the figure on your certificate describes the lot and not every tube inside it.
Two additions are available when the order calls for them. A stabilizing heat treatment, which A213 lists for TP321H, is run below the solution temperature at a figure agreed with you. An intergranular attack test run to ASTM A262 Practice E can also be specified; the standard notes that stabilization may be wanted for the titanium and niobium grades, particularly in their H versions, before that test is meaningful.
Designations of Grade 321H in Other Systems
Drawings reach us with several names for this steel. Only two of them control what we make: the UNS number and the A213 grade designation.
- ASTM / ASME tube gradeTP321H (A213 / SA-213)
- UNSS32109
- WNR, cross-reference only1.4878
- Russia (GOST)12X18H10T
European paperwork often names 1.4878 instead. We accept that line item and make it as TP321H to A213, printing 1.4878 beside the UNS number purely so your drawing and our certificate line up. A request for seamless WNR 1.4878 tube is therefore quoted, produced, tested and marked exactly as a TP321H request is.
Sizes and Permitted Variations of 321H Stainless Steel Seamless Tube
We draw the grade across the full tube envelope, and the dimensional variations A213 permits on our seamless tubing are what every item is measured against. Each 321H stainless steel seamless tube is checked against them before it is released.
Superheater and Reheater Sizes
Superheater and reheater work arrives as a list of diameters with a wall against each. Our range covers:
| Dimension | Figure |
|---|---|
| Outside diameter | 6.35 to 257 mm |
| Wall thickness | 0.89 to 12.7 mm |
| Straight length | Up to 22 m |
| Sizes A213 calls usual | 3.2 mm inside diameter up to 127 mm outside diameter, with 0.4 to 12.7 mm minimum wall |
| Larger diameters | Furnished under the clause that allows other diameters once every remaining requirement is met |
| Smallest tested sizes | Mechanical property requirements stop applying below 3.2 mm inside diameter or 0.4 mm wall |
Diameter Limit at the Largest Size the Standard Covers
Hot-finished tube at the top of the range is held to this row:
| Hot-finished tube, specified OD | Permitted Variation |
|---|---|
| Over 200 up to 225 mm | +0.4 / -1.6 mm |
The permitted variations stop at 225 mm. Diameters above that, up to the 257 mm we can draw, take the diameter limit written into our quotation instead.
Condition on delivery is covered as well. Tube is furnished reasonably straight, ends are left smooth and free of burrs, and a surface imperfection may be ground out so long as the wall remains within tolerance after grinding. Each UNS S32109 seamless tube also leaves marked with its heat number and the identification of its heat-treatment lot, the H-grade addition to the usual mark, specification, grade, finishing route and wall basis.
Where 321H Seamless Tubing Fits Beside 321 and 347H
A seamless stainless steel 321H tube and its non-H counterpart share the chromium and nickel bands and the same 515 MPa and 205 MPa minimums. What divides them is the treatment of carbon, capped in TP321 and held inside a window here, the titanium ratio, which TP321 sets at five times carbon plus nitrogen against four times for TP321H, and the grain size requirement, which only the H grade carries. Choose stainless steel 321 seamless tubes where stabilizing is wanted only to protect welded joints; choose 321H where creep decides the wall.
Niobium does the stabilizing in 347H seamless tubes, which follow the same H-grade rules on carbon and grain size and share the same 2000 F cold worked solution floor, a figure A213 converts as 1100 C there against 1090 C here. Strength minimums match, so the choice usually comes down to which stabilizer your specification or your welding procedure already names.
Applications of Seamless 1.4878 Stainless Steel Tube
Seamless 1.4878 stainless steel tube is specified where metal stays hot under load long enough for creep to govern the wall, and where welded joints have to keep their corrosion resistance through that service.
Flare Headers and Catalytic Cracking Units
Refinery flare headers and catalytic cracking units run hot hydrocarbon streams, and the stabilized structure gives the grade its resistance to polythionic acid stress corrosion cracking in refinery service. Sizes follow the unit drawing.
High-Heat Reactor Tubing in Chemical Plants
Reactor vessels and the heat-transfer tubing around them in chemical plants work hot and under pressure together. We cut to the lengths the vessel drawing gives and mark each piece to its lot.
Aerospace Exhaust Assemblies
High-temperature exhaust assemblies take the grade for its oxidation resistance and the strength it keeps when hot. Tube for these parts is usually ordered cold finished, to tighter surface and diameter requirements than pressure-part work.
Thermal Processing Equipment in Food Plants
Thermal processing equipment in food plants cycles its tube between hot and cold repeatedly. The titanium addition means welded sections keep their resistance to intergranular attack through that cycling without a further solution anneal.
Bundling, Documents and Dispatch
Bundles
Sorted by size and by heat, then strapped or packed into timber cases, with a plastic cap in every bore.
Long items
Stainless steel 321H seamless tubes approaching 22 m travel on closely spaced battens, so they arrive straight.
Records travelling with the goods
The EN 10204 3.1 (3.2 on request) certificate, a packing list itemized by size, the heat-treatment charts, 100% PMI results and the melt certificate for the billets.
Independent inspection
A third-party report is added to the file for orders that ask for one.
Commercial terms
The quotation names FOB, CIF or CFR.
Dispatch
Trucked to Thai sites, or containerized for sea freight.
What Seamless WNR 1.4878 Tube Costs per kg
Budget figures for seamless WNR 1.4878 tube to A213 TP321H run from about USD 4 to USD 7.5 per kg. Nickel and titanium set the base, and the H-grade work above it, the carbon window, the two solution temperatures and the grain size reading for every lot, lifts the figure. Thin walls, small diameters, bright annealing and short drawing runs sit at the upper end, and a firm price follows your size list.
Indicative price, Stainless Steel 321H Seamless Tubes
USD 4 to 7.5 per kg
Indicative only. Send your sizes and specification to Thaida for a firm quotation.
- Outside diameter
- Wall thickness
- Quantity
- Nickel price
- Titanium price
Manufacturing and Export of ASTM A213 Stainless Steel 321H Seamless Tubes
Every ASTM A213 stainless steel 321H seamless tube is drawn, annealed, tested and marked inside one factory: 154 Moo.1 Map Phai, Ban Bueng, Chonburi 20170, Thailand. Pricing, test certificates and export documents are issued from 89/18 Moo.15 Enterprize Park, Bangna-Trad Road, Bang Kaeo, Bang Phli, Samut Prakan 10540, Thailand. We reach plants throughout Thailand by road, and export consignments move by sea to Singapore, Malaysia, Vietnam, Indonesia, the Philippines and India. Our offer separates, size by size, the items ready to ship from those entering the next production run.
Factory154 Moo.1 Map Phai, Ban Bueng,
Chonburi 20170, Thailand
Chonburi 20170, Thailand
Office89/18 Moo.15 Enterprize Park, Bangna-Trad Road,
Bang Kaeo, Bang Phli, Samut Prakan 10540, Thailand
Bang Kaeo, Bang Phli, Samut Prakan 10540, Thailand
Exporting to
- Singapore
- Malaysia
- Vietnam
- Indonesia
- Philippines
- India
Seamless 321H Tubing FAQ
What does the 0.04 to 0.10% carbon window buy in a 321H seamless tube?
Creep-rupture strength. The 0.04% floor is what the H designation buys: A213 holds its H grades to requirements that reach a creep-rupture strength the plain grade does not normally achieve. The 0.10% ceiling stops carbon running past what the titanium can tie up.
Which solution temperature applies to cold worked and to hot rolled TP321H seamless tube?
The route decides it: 1090 °C (2000 °F) is the minimum for cold worked tube and 1050 °C (1925 °F) for hot rolled, with rapid cooling after either. Both are floors rather than setpoints, so write the route beside each size and the furnace chart will show which floor your lot was held above.
What grain size must a lot of seamless S32109 stainless steel tube meet?
No. 7 or coarser on the ASTM E112 scale. Because the test piece comes from one tube end in each lot, the figure is a lot result, so match the lot stamped on your tubes to the lot the certificate reports, item by item, when the delivery is checked in.
Why does an H-grade seamless tube carry a heat-treatment lot number?
Because the lot, not the single tube, owns the grain size and tension results. For its H grades A213 adds the heat number and the heat-treatment lot identification to the normal mark, so any tube found on site can be traced back to the test record written for it.
When is grade 347H the better choice than seamless 321H tube?
When the specification or the welding procedure is built around niobium stabilization instead of titanium. Both are A213 H types with the same tensile and yield minimums, the same grain size rule and the same 2000 F cold worked floor, converted as 1090 C here and 1100 C there. Send us the specification.
What surface and straightness condition does seamless 1.4878 tube arrive in?
Pickled clear of scale as standard, or unpickled where bright annealing has already left the surface clean. Ends come smooth and burr-free and the tube reasonably straight. Where a tighter surface is wanted, say so with the size list: exhaust and instrument work usually calls for cold finished, bright annealed tube.
Which extra requirements can be ordered on SS 321H seamless tubing?
Two: a stabilizing heat treatment, and an intergranular attack test to ASTM A262 Practice E. Both are ordered extras, so list them on the purchase order rather than assuming them. The stabilizing temperature is agreed case by case, and A213 pairs that test with stabilization for the titanium and niobium H grades.
What does the mill certificate for TP321H seamless tubing report?
Chemistry first: both analyses, heat and product, with carbon read against its 0.04 to 0.10% window. Then the lot results for tension, hardness, flattening, flaring and grain size, and the per-tube hydrostatic or nondestructive electric result. Everything appears under one EN 10204 3.1 (3.2 on request) certificate.
Request a Quote for Stainless Steel 321H Seamless Tubes
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