Project Description
444 stainless steel bar, also designated as UNS S44400, EN 1.4521 / X2CrMoTi18-2, JIS SUS444, is a nickel-free, molybdenum-alloyed ferritic stainless steel. With 1.8–2.5% molybdenum addition and titanium/niobium dual stabilization, 444 delivers pitting corrosion resistance comparable to 316L at a significantly lower cost. Its PRE value of approximately 25 makes it highly resistant to chloride-induced attack while its ferritic microstructure provides immunity to SCC. SHUNFU METAL supplies this cost-effective grade to the petroleum sector, where it outperforms 304L and matches 316L in many aggressive chloride-bearing environments without the nickel premium. The alloy was originally developed as a lower-cost alternative to 316L for hot water and heat exchanger applications, and has since been adopted by oil and gas operators seeking immunity to chloride SCC with a stable, predictable price point. Its thermal expansion coefficient is lower than that of austenitic grades, meaning 444 bar-machined components stay dimensionally accurate under temperature swings common in refinery and offshore service. At SHUNFU METAL, every heat of 444 bar is produced under ISO 9001:2015 and API Q1 certified quality management systems, with full traceability from melt to final shipment.
Equivalent Grades of 444 / S44400
444 is standardized globally under multiple designations. SHUNFU METAL certifies every bar to the buyer’s specified standard, issuing EN 10204 3.1 mill test certificates that reference the applicable ASTM, EN, JIS, or ISO grade. No direct GOST equivalent exists for this molybdenum-bearing ferritic grade, though 444 is occasionally cross-referenced in Russian procurement specifications as a substitute where 12X17 (430 type) lacks sufficient pitting resistance.
| Standard | Designation | Remarks |
|---|---|---|
| ASTM A276 | 444 / UNS S44400 | Stainless steel bars and shapes |
| ASTM A240 | 444 / UNS S44400 | Plate, sheet, and strip |
| EN 10088-3 | 1.4521 / X2CrMoTi18-2 | European bar standard |
| JIS G4303 | SUS444 | Japanese stainless bar |
| ISO 15510 | X2CrMoTi18-2 | International designation |
| GB/T 20878 | S11972 / 019Cr19Mo2NbTi | Chinese standard |
444 Bar in Oil & Gas Applications
The combination of 316L-grade pitting resistance, SCC immunity, and nickel-free cost structure makes 444 bar an increasingly specified material for petroleum equipment. SHUNFU METAL supplies 444 in bar form for the following oil and gas components — each manufactured under API Q1 quality assurance with full melt-to-component traceability.
Replaces 316L in shell-and-tube exchangers handling brackish cooling water at refineries.
Seamless tube-to-tubesheet joints in crude distillation unit overhead condensers, immune to chloride SCC.
High-pressure and low-pressure heater tubing in thermal recovery and power generation at oilfields.
Process and utility cooling water piping in offshore platforms and coastal refineries requiring high chloride resistance.
Flue gas desulfurization vessel internals, spray headers, and mist eliminator supports resisting sulfuric acid condensate.
Bar stock for agitator shafts, nozzle flanges, and manway components in acetic and formic acid service at petrochemical plants.
Bar-machined pump shafts, valve stems, and flange bolting for MSF and RO desalination on offshore production platforms.
Trim components and stems in low-H2S upstream gas processing where nickel-bearing alloys risk SCC.
Machined rings, retainers, and downhole tool bodies leveraging 444’s dimensional stability under thermal cycling.
Supply Range — 444 Stainless Steel Bar
SHUNFU METAL stocks and produces 444 bar in a wide dimensional range, manufactured under ISO 9001:2015 and API Q1 certified quality systems. Dual-stabilized 444 is readily hot-worked and cold-drawn, allowing us to supply the full spectrum from precision-ground small diameters to large forged sections for heavy-wall machined components. Every bar is fully traceable from melt to delivery, with incoming billets verified by OES and final products accompanied by EN 10204 3.1 mill test certificates.
| Product Form | Diameter/Thickness | Length | Surface |
|---|---|---|---|
| Hot rolled round bar | 8–300 mm | 3000–12000 mm | Black / Peeled / Ground |
| Cold finished round bar | 3–120 mm | 2000–6000 mm | H9–H11 tolerance / Bright |
| Hot rolled flat bar | Thk 5–120 mm, W 15–350 mm | 3000–12000 mm | Black / Machined edges |
| Forged round bar | 50–800 mm | 2000–8000 mm | Rough turned / Machined |
| Forged flat / block | Thk 40–400 mm, W 100–600 mm | 1000–6000 mm | Machined all sides |
Cut-to-length and non-standard sizes available on request. SHUNFU METAL performs 100% dimensional inspection and optional UT / PT non-destructive testing per ASTM A388 or EN 10228-3 prior to dispatch.
Chemical Composition of 444 Per ASTM A240
| Element | C | Mn | Si | P | S | Cr | Mo | Ni | N | Ti+Nb |
|---|---|---|---|---|---|---|---|---|---|---|
| Wt% | 0.025 max | 1.00 max | 1.00 max | 0.040 max | 0.030 max | 17.5–19.5 | 1.75–2.50 | 1.00 max | 0.035 max | 0.20+4(C+N) min |
SHUNFU METAL sources only dual-stabilized (Ti + Nb) heats from ISO 9001-certified steel mills. Titanium and niobium additions tie up carbon and nitrogen, preventing chromium carbide precipitation at grain boundaries during welding and ensuring as-welded corrosion resistance without post-weld heat treatment — a critical advantage for field-fabricated piping and vessel components. Incoming billets undergo OES verification at SHUNFU METAL’s in-house laboratory before being released to production, with chemistry results recorded against each heat number in the traceability system.
Mechanical Properties of 444 Stainless Steel Bar
Values below represent annealed condition per ASTM A276 and EN 10088-3, verified by SHUNFU METAL on every production lot through in-house tensile and hardness testing. Heat treatment at SHUNFU METAL is performed in computer-controlled furnaces with multi-zone thermocouple monitoring, achieving uniform grain structure and consistent mechanical properties across the full cross-section.
| Property | Condition | Typical Value | Standard |
|---|---|---|---|
| Tensile strength, Rm | Annealed | 415–650 MPa | ASTM A276 |
| Yield strength, Rp0.2 | Annealed | ≥ 310 MPa | ASTM A276 |
| Elongation, A5 | Annealed | ≥ 20% | ASTM A276 |
| Brinell hardness | Annealed | ≤ 217 HB | ASTM A276 |
| Rockwell hardness | Annealed | ≤ 96 HRB | ASTM A276 |
| Reduction of area | Annealed | ≥ 45% | ASTM A276 |
| Elastic modulus | 20°C | 200 GPa | Typical |
The molybdenum addition raises yield strength beyond standard 430 while the dual-stabilized chemistry preserves ductility after welding and thermal cycling. At SHUNFU METAL, annealing is conducted at 950–1050°C followed by air cooling or water quenching, with every batch hardness-tested before release and tensile coupons pulled from each heat for mechanical property verification. The alloy’s higher creep resistance relative to unstabilized ferritics makes it suitable for components operating up to 400°C in refinery heat recovery systems and moderate-temperature process equipment. PRE calculation: PRE = Cr + 3.3 × Mo ≈ 18.5 + 3.3 × 2.1 ≈ 25.4, placing 444 between 304L (PRE ≈ 19) and 316L (PRE ≈ 26), confirming its position as a true cost-competitive alternative to molybdenum-bearing austenitics for chloride service in the oil and gas industry.