• Two premium austenitic forged ring grades: 316L (1.4404) and super austenitic 904L (1.4539), compliant with ASTM A182 standard
• 316L with molybdenum element for standard chloride & mild acid anti-corrosion performance
• 904L high nickel-molybdenum super austenitic grade for strong mixed acid & high-chloride harsh media
• Ultra-low carbon design for both grades, eliminate intergranular corrosion after welding & thermal cycles
• Stable single-phase austenite matrix, non-magnetic, excellent ductility & full weldability
• Uniform uninterrupted grain flow via radial seamless ring rolling, high pressure bearing capacity
• Custom OD, ID, height and full CNC turning, boring, grooving per customer CAD/PDF drawings
• Widely applied in food, pharmaceutical, marine desalination and heavy chemical equipment

This series of austenitic stainless steel forged rings are manufactured by open-die forging and radial-axial ring rolling process. After full solution annealing and water quenching treatment, uniform stable austenite microstructure is formed without harmful precipitates.

316L is the universal molybdenum-bearing austenitic stainless steel, suitable for medium chloride, food and general chemical environments with balanced cost and corrosion resistance. 904L belongs to super austenitic stainless steel, featuring high Ni-Mo-Cu composite formula, outstanding tolerance to mixed sulfuric-phosphoric acid, high-concentration brine and industrial waste liquid, which cannot be satisfied by regular duplex and 316L steel. Seamless forged ring blanks save massive solid bar deep boring workload, commonly processed into pressure vessel flanges, heat exchanger tube sheet rings, reactor sealing rings and pipeline connecting annular components.

Low-carbon molybdenum austenitic stainless steel. Molybdenum improves resistance to pitting and crevice corrosion in seawater and weak acids; low carbon avoids welding intergranular corrosion; non-magnetic, easy forming and welding, cost-effective for most medium corrosive industrial scenarios.

High nickel-molybdenum-copper super austenitic alloy. Unique Cu addition enhances reducing acid resistance; extremely high PRE value resists high chloride SCC; stable service in hot sulfuric acid, phosphoric acid and pickling media, ideal heavy-duty chemical equipment blank.

• Austenitic Stainless Steel: 304, 316L, 321, 347, 310S, 904L, 254SMo
• Duplex Stainless Steel: 2205, 2507, S32750, F51, F55
• Ferritic Stainless Steel: 409, 430, 439, 444
• Martensitic Stainless Steel: 410, 420, 440C
• PH Stainless Steel: 17-4PH, 15-5PH, 17-7PH
• Nickel Base Alloys: Monel400/K500, Incoloy825, Inconel600/625, Hastelloy C276
• Alloy & Carbon Steel: A105, 4140, F22, F91, A516 Gr.70

316L for standard marine & food industry; 904L super austenitic solves strong mixed acid high-chloride corrosion issues that duplex steel cannot handle.

Both grades adopt ultra-low carbon formula, no carbide precipitation during welding or long heating, welded rings keep full corrosion resistance without post heat treatment.

Single-phase austenite non-magnetic matrix, great ductility for turning, milling, bending and all complex forming processes.

Continuous metal fiber improves fatigue and pressure resistance of annular forgings, suitable high-pressure vessel flange blanks.

Smooth non-porous surface easy to clean, meet strict hygiene standards for food & pharmaceutical production equipment.

• 316L Forged Rings: Food machinery flanges, pharmaceutical equipment ring parts, seawater cooling pipeline fittings, municipal water treatment vessel rings, architectural structural annular components
• 904L Forged Rings: Sulfuric & phosphoric acid reactor tube sheets, pickling line heat exchanger flanges, waste gas desulfurization equipment holding rings, high-salinity brine desalination pressure vessel blanks, chemical fertilizer production annular forgings

We provide integrated open-die forging & seamless ring rolling production, full CNC precision machining per customer CAD/PDF drawings:

• Rough cutting, facing, inner & outer diameter turning, ring height milling
• Precision boring, grooving, drilling, threading, chamfering & mirror polishing
• Solution annealing + water quenching heat treatment customization
• Surface pickling, passivation, electropolishing finishing treatment

We supply 316L & 904L austenitic forged rings, flanges and tube sheet blanks for food, marine, pharmaceutical and heavy chemical global clients.

• 100% UT Ultrasonic Testing to detect forging lamination, crack & internal defects
• Full batch tensile, yield & hardness mechanical performance inspection
• High-precision caliper & CMM for OD/ID/height dimensional tolerance control
• Spectrometer full spectrum chemical composition analysis per heat lot
• Metallographic austenite microstructure ratio inspection

Mill Test Certificate EN 10204 3.1 can be issued and delivered with shipment documents before delivery.

- Inner layer: Waterproof anti-rust plastic full wrap + separate plastic protective sleeves

- Outer layer: Reinforced fumigated wooden pallet / wooden case with separation blocks to avoid collision deformation

- Custom heavy-duty export packaging available upon customer request

Normally 10 – 45 working days after receiving advance payment. Exact lead time depends on ring OD/ID size, height, order quantity and custom machining demands.