S31400  is high-silicon 25-20 austenitic heat-resistant stainless steel bright bar. Silicon content (1.5%~3.0%) is significantly increased compared with 310S,  The Si-Cr composite oxide film delivers ultra-high temperature oxidation resistance, specially designed for carburizing furnaces and radiant tubes.
It has balanced room-temperature mechanical properties with sufficient tensile & yield strength and good ductility. It cannot be hardened by heat treatment; cold working causes work hardening, while solution annealing at 1100~1150℃ restores ductility. It features excellent thermoplasticity for smooth high-temperature forging & hot rolling, with stable performance for turning, milling, drilling and CNC machining.
Core advantages: High silicon forms dense high-temperature anti-oxidation scale, stable long-term service at 1000~1100℃, short-term peak up to 1150℃. Its oxidation, carburization and sulfidation resistance, as well as high-temperature creep & stress rupture strength are far superior to 310S, resisting deformation and scaling under high-temperature load.
Limitations: High carbon content leads to chromium carbide precipitation and intergranular corrosion sensitization after welding; long-term service at 650~900℃ precipitates brittle σ-phase; poor resistance to seawater, chloride ions and strong reducing wet corrosion, only suitable for dry high-temperature oxidizing, carburizing and sulfur-containing flue gas environments.

Chemical element content (%)

Specification：1.00~300.00mm

Application:It is mainly used to manufacture carburizing furnace radiant tubes, high-temperature furnace rollers, kiln load-bearing supports, annealing tray mandrels, heat treatment tool bars, incinerator flue high-temperature shafts, petrochemical cracking furnace fasteners, gas burner core rods, ceramic kiln high-temperature bolts, metallurgical furnace supports, heat treatment mesh belt shafts, furnace anchors, etc.
Widely applied in industrial carburizing & nitriding furnaces, waste incineration waste heat boilers, petrochemical cracking units, ceramic sintering kilns, thermal power boiler auxiliary parts, metallurgical heating equipment, photovoltaic sintering furnaces, continuous heat treatment production lines and other industries.

Core Advantages Over Competitors

1. High quality stability: Full closed-loop production & online spectral inspection strictly control C, Cr, Ni, Si with silicon stably limited 1.5~3%. Uniform segregation-free austenitic microstructure ensures negligible batch fluctuation of oxidation & creep performance for consistent mass production of furnace parts.

2. Excellent surface quality: Dedicated high-precision cold drawing & grinding lines deliver bars free of scale, scratches and pits. Smooth surface reduces alternating thermal stress concentration to extend service life of carburizing furnace components; secondary polishing is unnecessary for most machining.

3. Ultra-high dimensional accuracy: Precision rolling mills & automatic online detectors narrow tolerances with tiny single-bar error and strong batch uniformity, unifying part sizes in automatic mass production to raise yield.

4. Rich product variety: According to market demand and customer's special requirements, customized S31400 bright bar products are provided to meet the use requirements under various complex working conditions, providing customers with more choices.

5. Perfect after-sales service: The perfect after-sales service system can respond to customer needs and feedback in a timely manner. For problems encountered by customers during use, technical support and solutions are provided to customers quickly.

We mainly engage in cold heading wire, bar, peeled bar, and profiled bar; our products cover 11 series and more than 300 grades, and we continue to develop a variety of professional steels. We can provide all-round solutions such as cold heading finishing line manufacturing and high-precision bright bar customization, and provide one-stop procurement services and package procurement solutions for global customers. The website displays some grades. If you don’t have the grade you need, please contact us by phone or email.