Womic Stainless Steel Co., Ltd
Exceptional Seawater Corrosion Resistance: Outstanding resistance to pitting, crevice corrosion, and biofouling in seawater and brackish water environments, with no reported failures in marine service.
Superior Chloride Stress Corrosion Cracking Resistance: High nickel content (≥58%) provides outstanding resistance to chloride-induced SCC, outperforming all stainless steel and duplex grades.
Excellent High-Temperature Strength: Maintains excellent mechanical properties up to 980°C (1800°F), with solid solution strengthening providing high creep resistance.
Outstanding Pitting Resistance Equivalent (PRE): PRE ≥ 45 due to high molybdenum (8-10%) and niobium (3.15-4.15%) content, providing superior localized corrosion resistance.
Excellent Weldability and Formability: Unlike many high-strength alloys, Inconel 625 exhibits excellent weldability with matching filler metals (ERNiCrMo-3) and can be welded to a wide range of materials.
Surface Quality: Smooth internal and external surfaces available in annealed, pickled, or polished conditions for critical applications.
Mechanical Strength: High tensile and yield strength suitable for high-pressure downhole tubing, subsea umbilicals, and critical structural applications.
Oxidation and Carburization Resistance: High chromium content provides excellent resistance to oxidation and carburization up to 980°C.
International Certification: Tubes can be certified by ABS, BV, DNV, LR, GL, RINA, CCS, KR, and NK, and comply with NACE MR0175/ISO 15156, API 6A, API 17E, ISO 13628-5 (Subsea Umbilicals) , and NORSOK M-650 standards.
The Inconel 625 Superalloy Steel Tubes produced by Womic Steel conform to multiple international specifications used in marine, oil & gas, aerospace, and pressure applications:
|
Standard |
Description |
Equivalent Grade / Material Number |
|
ASTM B444 / ASME SB444 |
Seamless nickel-chromium-molybdenum alloy pipe and tube |
UNS N06625 (Inconel 625) |
|
ASTM B704 / ASME SB704 |
Welded nickel alloy tube for boiler, heat exchanger, and condenser |
UNS N06625 |
|
AMS 5581 |
Aerospace Material Specification – Seamless tubing |
Inconel 625 |
|
API 6A |
Wellhead and Christmas tree equipment |
Inconel 625 |
|
API 17E |
Subsea umbilicals – specification |
Inconel 625 |
|
ISO 13628-5 |
Subsea umbilicals – recommended practice |
Inconel 625 |
|
NACE MR0175 / ISO 15156 |
Sour service compliance |
Inconel 625 |
|
NORSOK M-650 |
Qualification of special materials |
Inconel 625 |
|
EN 10216-5 |
Seamless stainless steel tubes for pressure purposes |
2.4856 (NiCr22Mo9Nb) |
|
DIN 17751 |
Nickel alloy tubes |
NiCr22Mo9Nb |
|
ISO 6207 |
Nickel alloy seamless tubes |
NiCr22Mo9Nb |
These standards ensure that Inconel 625 Superalloy Steel Tubes meet global requirements for chemical composition, mechanical performance, testing, and dimensional accuracy.
Different specifications can be customized according to special requirements.
|
Execution Standard |
Main Standard |
Standard Grade |
|
ASTM (USA) |
ASTM B444, B704, B705, B829 |
Inconel 625 (N06625), Inconel 718 (N07718), Inconel 600 (N06600), Inconel 825 (N08825), Hastelloy C276 (N10276) |
|
ASME (USA) |
SB444, SB704, SB705, SB829 |
Inconel 625, Inconel 718, Inconel 600, Inconel 825, Hastelloy C276 |
|
API (International) |
API 6A, API 17E |
Inconel 625, Inconel 718 |
|
ISO (International) |
ISO 13628-5, ISO 6207 |
NiCr22Mo9Nb (2.4856), NiCr19NbMo (2.4668) |
|
EN / DIN (Europe) |
EN 10216-5, EN 10217-7 |
2.4856 (Inconel 625), 2.4668 (Inconel 718), 2.4816 (Inconel 600), 2.4858 (Inconel 825), 2.4819 (Hastelloy C276) |
|
NACE (International) |
NACE MR0175 / ISO 15156 |
Inconel 625, Inconel 718, Inconel 825, Hastelloy C276 |
|
Element |
Ni |
Cr |
Fe |
Mo |
Nb+Ta |
Ti |
Al |
C |
Mn |
P |
S |
Si |
Co |
|
Inconel 625 |
≥58.0 |
20.0–23.0 |
≤5.0 |
8.0–10.0 |
3.15–4.15 |
≤0.40 |
≤0.40 |
≤0.10 |
≤0.50 |
≤0.015 |
≤0.015 |
≤0.50 |
≤1.0 |
Note: Inconel 625 is a solid solution strengthened nickel-chromium-molybdenum alloy with niobium addition for stabilization. The high molybdenum and niobium content provide exceptional pitting resistance (PRE ≥ 45), significantly outperforming stainless steel and duplex grades. The alloy exhibits excellent corrosion resistance in seawater, sour gas (H₂S), and a wide range of acids including hydrochloric, sulfuric, and phosphoric acid.
Comparison of PRE (Pitting Resistance Equivalent) Values:
|
Grade |
PRE |
Seawater Suitability |
|
304/304L Stainless |
18-19 |
Poor |
|
316/316L Stainless |
24-26 |
Limited |
|
Duplex 2205 |
≥34 |
Good |
|
Super Duplex 2507 |
≥42 |
Excellent |
|
Inconel 625 |
≥45 |
Outstanding |
The Inconel 625 Superalloy Steel Tube offers balanced strength and ductility, making it suitable for forming, welding, and high-pressure applications.
|
Property |
Unit |
Inconel 625 (Annealed) |
|
Tensile Strength (min) |
MPa |
≥825 |
|
Yield Strength (min) |
MPa |
≥415 |
|
Elongation (min) |
% |
≥30 |
|
Hardness (typical) |
HRC |
≤25 |
|
Density |
g/cm³ |
8.44 |
|
Melting Range |
°C |
1290–1350 |
|
Thermal Conductivity (20°C) |
W/m·K |
9.8 |
|
Coefficient of Thermal Expansion (20–100°C) |
μm/m·K |
12.8 |
|
Modulus of Elasticity (20°C) |
GPa |
205 |
High-Temperature Tensile Properties (Typical Values) :
|
Temperature (°C) |
Tensile Strength (MPa) |
Yield Strength (MPa) |
|
20 |
900–1000 |
450–550 |
|
400 |
800–900 |
380–480 |
|
600 |
700–800 |
360–460 |
|
800 |
450–550 |
200–280 |
|
980 |
200–280 |
80–120 |
Inconel 625 Superalloy Steel Tube – Heat Treatment Condition:
Inconel 625 tubes are solution annealed at 1095–1205°C followed by water quenching. This heat treatment:
Dissolves precipitated carbides and intermetallic phases.
Relieves internal stresses from cold drawing or cold pilgering.
Restores optimum corrosion resistance and ductility.
Ensures the alloy's exceptional resistance to corrosive attack.
Inconel 625 Superalloy Steel Tube – Delivery Condition:
Tubes are normally supplied in annealed and pickled condition, providing a clean, smooth surface and excellent corrosion resistance. Upon request, bright annealed (BA) , polished, or cold worked finishes can be provided to meet specific requirements.
Womic Steel adopts advanced production technology to ensure each Inconel 625 Superalloy Steel Tube meets exact specifications and flawless surface quality.
Raw Material Selection: High-quality Inconel 625 billets from certified premium mills (Special Metals, ATI, Carpenter, VDM Metals) with certified chemical composition and traceability. Material is VIM-VAR (Vacuum Induction Melted – Vacuum Arc Remelted) for optimal cleanliness.
Heating and Piercing: Billets heated to a controlled temperature range (1100–1200°C) and pierced using a rotary piercing mill to form hollow shells.
Hot Rolling: Shells elongated and rolled to desired intermediate size with strict temperature control.
Cold Drawing / Cold Pilgering: Tubes refined to precise dimensions and improved surface finish. Multiple passes with intermediate annealing required due to work hardening.
Solution Annealing: Heat treatment at 1095–1205°C followed by water quenching to restore corrosion resistance and ductility.
Pickling & Passivation: Removal of oxides and creation of passive film for enhanced corrosion protection.
Straightening and Dimensional Calibration: Ensures consistent roundness and wall uniformity.
Final Inspection & Marking: Each tube tested, marked with grade, heat number, standard, and tube dimensions before packing.
This process guarantees a smooth internal bore, high structural integrity, and exceptional corrosion resistance across all batches of Womic Steel’s Inconel 625 Superalloy Steel Tubes.
Womic Steel utilizes state-of-the-art manufacturing technology to ensure every Inconel 625 Welded Superalloy Steel Tube meets precise specifications and delivers excellent surface quality and performance.
Raw Material Selection: High-quality Inconel 625 strips/coils from certified premium mills with full traceability.
Slitting & Uncoiling: The steel coil is slit to the required width and uncoiled for feeding into the forming mill.
Forming & Welding: The strip is progressively formed into a cylindrical shape and the edges are welded together using advanced TIG or Plasma welding techniques with matching filler metal (ERNiCrMo-3) to create a solid weld seam.
Weld Seam Treatment: The external weld bead is removed to achieve a smooth surface, and the internal bead may be controlled or treated for bore cleanliness.
Solution Annealing: A full heat treatment process is applied to dissolve carbides, restore corrosion resistance, and relieve stresses from welding and forming.
Sizing & Calibration: The tube is passed through a sizing mill to achieve the final precise outer diameter and roundness.
Straightening: The tube is straightened to ensure optimal linearity.
Pickling & Passivation: Chemical treatment removes scale and impurities, while promoting the formation of a protective passive oxide layer on the surface, including the weld zone.
Non-Destructive Testing (NDT) : The weld seam is inspected using methods like Eddy Current or Ultrasonic Testing to ensure integrity and quality.
Final Inspection & Marking: Each tube undergoes dimensional checks, visual inspection, and is marked with grade, heat number, and relevant standards before packaging.
This controlled process guarantees a consistent weld seam, excellent dimensional accuracy, and superior corrosion resistance for every batch of Womic Steel’s Inconel 625 Welded Superalloy Steel Tubes.
Outside Diameter: 1.6mm – 152mm (1/16″ – 6″)
Wall Thickness: 0.3mm – 12.7mm (0.012″ – 0.500″)
Length: Up to 30m (straight lengths); coiled tubing up to 1000m available
OD Tolerances:
Standard: ±0.08mm
Precision: ±0.03mm (upon request)
Wall Thickness Tolerances:
Standard: ±8% of nominal
Precision: ±5% of nominal (upon request)
Straightness: 0.3mm per 1000mm length typical
|
ANSI B 36.19/ANSI B36.10 DIMENSIONS OF SEAMLESS &WELDED STAINLESS STEEL PIPE |
|||||||||||||||||||
|
Nominalsize |
mm |
ANSIB36.19 |
ANSIB36.10ANSIB36.10 |
||||||||||||||||
|
DN |
NPS |
mm |
5S |
10S |
40S |
80S |
10 |
20 |
30 |
STD |
40 |
60 |
XS |
80 |
100 |
120 |
140 |
160XXS |
|
|
6 |
1/8" |
10.29 |
|
1.24 |
1.73 |
2.41 |
|
|
|
1.73 |
1.73 |
|
2.41 |
2.41 |
|
|
|
|
|
|
8 |
1/4" |
13.72 |
|
1.65 |
2.24 |
3.02 |
|
|
|
2.24 |
2.24 |
|
3.02 |
3.02 |
|
|
|
|
|
|
10 |
3/8" |
17.15 |
|
1.65 |
2.31 |
3.20 |
|
|
|
2.31 |
2.31 |
|
3.20 |
3.20 |
|
|
|
|
|
|
15 |
1/2" |
21.34 |
1.65 |
2.11 |
2.77 |
3.73 |
|
|
|
2.77 |
2.77 |
|
3.73 |
3.73 |
|
|
|
4.78 |
7.47 |
|
20 |
3/4" |
26.67 |
1.65 |
2.11 |
2.87 |
3.91 |
|
|
|
2.87 |
2.87 |
|
3.91 |
3.91 |
|
|
|
5.56 |
7.82 |
|
25 |
1" |
33.4 |
1.65 |
2.77 |
3.38 |
4.55 |
|
|
|
3.38 |
3.38 |
|
4.55 |
4.55 |
|
|
|
6.35 |
9.09 |
|
32 |
1 1/4" |
42.16 |
1.65 |
2.77 |
3.56 |
4.85 |
|
|
|
3.56 |
3.56 |
|
4.85 |
4.85 |
|
|
|
6.35 |
9.70 |
|
40 |
1 1/2" |
48.26 |
1.65 |
2.77 |
3.68 |
5.08 |
|
|
|
3.68 |
3.68 |
|
5.08 |
5.08 |
|
|
|
7.14 |
10.16 |
|
50 |
2" |
60.33 |
1.65 |
2.77 |
3.91 |
5.54 |
|
|
|
3.91 |
3.91 |
|
5.54 |
5.54 |
|
|
|
8.74 |
11.07 |
|
65 |
2 1/2" |
73.03 |
2.11 |
3.05 |
5.16 |
7.01 |
|
|
|
5.16 |
5.16 |
|
7.01 |
7.01 |
|
|
|
9.52 |
14.02 |
|
80 |
3" |
88.9 |
2.11 |
3.05 |
5.49 |
7.62 |
|
|
|
5.49 |
5.49 |
|
7.62 |
7.62 |
|
|
|
11.13 |
15.24 |
|
90 |
3 1/2" |
101.6 |
2.11 |
3.05 |
5.74 |
8.08 |
|
|
|
5.74 |
5.74 |
|
8.08 |
8.08 |
|
|
|
|
|
|
100 |
4" |
114.3 |
2.11 |
3.05 |
6.02 |
8.56 |
|
|
|
6.02 |
6.02 |
|
8.56 |
8.56 |
|
11.13 |
|
13.50 |
17.12 |
|
125 |
5” |
141.3 |
2.77 |
3.40 |
6.55 |
9.52 |
|
|
|
6.55 |
6.55 |
|
9.52 |
9.52 |
|
12.70 |
|
15.90 |
19.05 |
|
150 |
6" |
168.28 |
2.77 |
3.40 |
7.11 |
10.97 |
|
|
|
7.11 |
7.11 |
|
10.97 |
10.97 |
|
14.30 |
|
18.20 |
21.95 |
|
200 |
8" |
219.08 |
2.77 |
3.76 |
8.18 |
12.70 |
|
6.35 |
7.04 |
8.18 |
8.18 |
10.30 |
12.70 |
12.70 |
15.10 |
18.20 |
20.60 |
23.00 |
22.22 |
|
250 |
10" |
273.05 |
3.40 |
4.19 |
9.27 |
12.70 |
|
6.35 |
7.80 |
9.27 |
9.27 |
12.70 |
12.70 |
15.09 |
18.26 |
21.44 |
25.40 |
28.58 |
|
|
300 |
12" |
323.85 |
3.96 |
4.57 |
9.52 |
12.70 |
|
6.35 |
8.38 |
9.52 |
10.31 |
14.27 |
12.70 |
17.48 |
21.44 |
25.40 |
28.58 |
33.32 |
|
|
350 |
14" |
355.6 |
3.98 |
4.78 |
|
|
6.35 |
7.92 |
9.52 |
9.52 |
11.13 |
15.09 |
12.70 |
19.05 |
23.83 |
27.79 |
31.75 |
35.71 |
|
|
400 |
16" |
406.4 |
4.19 |
4.78 |
|
|
6.35 |
7.92 |
9.52 |
9.52 |
12.70 |
16.66 |
12.70 |
21.44 |
26.19 |
30.96 |
36.53 |
40.49 |
|
|
450 |
18" |
459.2 |
4.19 |
4.78 |
|
|
6.35 |
7.92 |
11.13 |
9.52 |
14.27 |
19.05 |
12.70 |
23.83 |
29.36 |
34.92 |
39.67 |
45.24 |
|
|
500 |
20" |
508 |
4.77 |
5.53 |
|
|
6.35 |
9.52 |
12.70 |
9.52 |
15.09 |
20.62 |
12.70 |
26.19 |
32.54 |
38.10 |
44.45 |
50.01 |
|
|
550 |
22" |
558.8 |
4.77 |
5.53 |
|
|
6.35 |
9.52 |
12.70 |
9.52 |
15.87 |
22.22 |
12.70 |
28.57 |
34.92 |
41.27 |
47.62 |
53.97 |
|
|
600 |
24" |
609.6 |
5.54 |
6.35 |
|
|
6.35 |
9.52 |
14.70 |
9.52 |
17.48 |
24.61 |
12.70 |
30.96 |
38.89 |
46.02 |
52.37 |
59.94 |
|
|
650 |
26" |
660.4 |
|
|
|
|
7.92 |
12.70 |
|
9.52 |
|
|
12.70 |
|
|
|
|
|
|
|
700 |
28" |
711.2 |
|
|
|
|
7.92 |
12.70 |
15.88 |
9.52 |
|
|
12.70 |
|
|
|
|
|
|
|
750 |
30" |
762 |
6.35 |
7.92 |
|
|
7.92 |
12.70 |
15.88 |
9.52 |
|
|
12.70 |
|
|
|
|
|
|
|
800 |
32" |
812.8 |
|
|
|
|
7.92 |
12.70 |
15.88 |
9.52 |
|
|
12.70 |
|
|
|
|
|
|
Womic Steel offers a wide range of surface finishes to meet various industrial, marine, and critical service applications.
|
Surface Type |
Description |
|
Annealed & Pickled (AP Finish) |
Standard industrial finish – matte, oxide-free after acid treatment. Suitable for most marine and chemical applications. |
|
Bright Annealed (BA Finish) |
Mirror-like surface obtained through controlled atmosphere annealing. |
|
Polished Finish (180#, 240#, 320#, 400#) |
Smooth mechanical finish suitable for high-purity and instrumentation applications. |
|
Cold Worked Finish |
As-drawn finish with higher strength (cold worked condition). |
|
Passivated Finish |
Surface chemically treated to enhance corrosion protection. |
|
Electropolished Finish |
Extremely clean, smooth, and hygienic finish ideal for pharmaceutical and high-purity applications. |
Each Inconel 625 Superalloy Steel Tube surface is inspected for uniform appearance, absence of pits, and consistent finish quality.
Every Inconel 625 Superalloy Steel Tube undergoes comprehensive inspection in accordance with ASTM, API, and NACE standards to guarantee reliability and performance:
|
Test / Inspection |
Description |
Applicability |
|
Visual & Dimensional Inspection |
Surface, roundness, and thickness checked. |
100% |
|
Hydrostatic Pressure Test |
100% tested for leakage and pressure resistance. |
100% |
|
Eddy Current Test (ECT) |
Detects surface and sub-surface imperfections. |
100% |
|
Ultrasonic Test (UT) |
Ensures internal integrity of the seamless structure. |
Upon request |
|
Positive Material Identification (PMI) |
Confirms correct chemical grade of the Inconel 625 tube. |
100% (per heat) |
|
Intergranular Corrosion Test (IGC) |
ASTM G28 – validates resistance to intergranular corrosion. |
Per heat / batch |
|
Pitting Corrosion Test |
ASTM G48 – ferric chloride pitting test. |
Upon request |
|
Flattening & Flaring Tests |
Evaluate ductility and deformation capability. |
Per heat / batch |
|
Hardness & Tensile Testing |
Confirms mechanical compliance with ASTM standards. |
Per heat / batch |
|
Surface Roughness and Cleanliness Check |
For polished or instrument tubes. |
Upon request |
|
Third-Party Inspection (SGS / BV / DNV / TUV) |
Available upon customer request. |
Upon request |
These extensive tests ensure that every Inconel 625 Superalloy Steel Tube from Womic Steel meets the highest international standards for reliability and longevity.
Inconel 625 Superalloy Steel Tube is ideal for a wide variety of industries, offering long service life and corrosion resistance in demanding conditions:
|
Industry |
Typical Applications |
|
Marine & Shipbuilding |
Propulsion system tubing, seawater cooling lines, ballast system instrumentation, hydraulic lines, exhaust gas scrubber tubing (ship classification certifications available from ABS, BV, DNV, LR, GL, RINA, CCS, KR, NK). |
|
Oil & Gas (Downhole) |
Downhole production tubing, chemical injection lines, subsea umbilicals, control lines, wellhead components, Christmas tree tubing, landing string components (NACE MR0175 compliant, API 6A, API 17E, ISO 13628-5). |
|
Subsea Engineering |
Umbilical tubes for subsea production systems, MEG injection lines, hydraulic control lines, chemical injection lines. |
|
Aerospace |
Hydraulic system tubing, fuel system components, pneumatic control lines, engine bleed air ducts, thrust reverser actuator lines. |
|
Chemical Processing |
Chemical injection tubing, reactor instrumentation, high-temperature corrosive service lines, acid handling systems, chlorine dioxide service. |
|
Nuclear Power |
Reactor instrumentation tubes, control rod mechanism tubing, coolant system components, spent fuel handling equipment. |
|
Power Generation |
Boiler instrumentation tubing, high-temperature pressure lines, gas turbine control lines, steam sampling lines. |
|
Desalination Plants |
High-pressure brine instrumentation tubing, chemical injection lines, control system tubing. |
|
Pharmaceutical |
High-purity process lines, sterile transfer lines, clean steam systems. |
|
Hydrogen Service |
High-pressure hydrogen handling tubing, fuel cell systems, hydrogen refueling station tubing. |
Each Inconel 625 Superalloy Steel Tube is securely packed and clearly labeled to ensure safe and efficient transport worldwide.
General
packaging for local truck transport:
Bundle packing with woven fabric, iron strip bundle, plastic cap on two ends.
Hexagonal
packaging:
Bundle packing with woven fabric, iron strip bundle, plastic cap on two ends.
Packaging
for welded tube in medium and large sizes:
Wrapped with woven fabric by automatic packaging for export sea-worthy transport.
Packaging
for medium and large size welded tubes to be exported:
Wooden or steel crate packaging for export sea-worthy transport.
General
packaging for products to be exported:
Wooden box for export sea-worthy transport.
Packaging
for instrumentation and coiled tubing:
Wooden box or steel reels for export sea-worthy transport.
Direct cooperation with global shipowners ensures the most competitive freight rates.
Professional loading and securing teams guarantee damage-free shipment.
Efficient document preparation (EN 10204 3.1/3.2 certificates, MTR, NACE compliance certificates), minimizing customs delays.
Rapid delivery time — select sizes kept in ready stock.
Continuous cargo tracking and after-sales follow-up to ensure smooth arrival at destination.
Womic Steel is a trusted manufacturer and exporter specializing in Inconel 625 Superalloy Steel Tubes, committed to delivering premium quality and professional service.
Strict quality control under ISO 9001, PED, and ASME certification.
Marine certified – ABS, BV, DNV, LR, GL, RINA, CCS, KR, NK approvals available.
Oil & gas qualified – NACE MR0175, API 6A, API 17E, ISO 13628-5 compliance.
Modern production lines and experienced technicians.
Complete testing, inspection, and documentation support.
Flexible customization and surface finishing options.
Fast production cycle and reliable global shipping.
Premium mill relationships – direct sourcing from Special Metals, ATI, Carpenter, VDM Metals.
Full traceability – from melt to final tube, complete certification package.
