321 is titanium-stabilized general austenitic stainless steel bright bar. Titanium is added on the basis of 304 with Ti ≥5×C and C ≤0.08%. Titanium preferentially combines with carbon to form stable TiC, preventing chromium depletion at grain boundaries and eliminating intergranular corrosion after welding or long-term high-temperature service.
It presents single-phase austenite and nearly non-magnetic after solution annealing. Balanced room-temperature mechanical properties, excellent plasticity, deep drawability and cold heading performance enable uniform plastic deformation without brittle fracture. It cannot be hardened by heat treatment; cold working leads to work hardening, while high toughness can be restored via solution annealing at 980~1080℃.
Chemical element content (%)
C | Si | Mn | P | S | |
Min | - | - | - | - | - |
Max | 0.08 | 1 | 2 | 0.045 | 0.03 |
Please note that the specific content may fluctuate under different production batches and technical requirements.
Specification:1.00~300.00mm
Balanced room-temperature strength
Excellent high-temperature thermoplasticity
Excellent plasticity & ductility
High surface finish
General machinability
Excellent medium-temperature creep resistance
Application: It is mainly used to manufacture boiler pipe fasteners, automotive exhaust valve stems, medium-temperature heat exchanger mandrels, heat treatment furnace tool bars, steam pipe flanges, high-temperature sterilization equipment connectors, power plant medium-temperature auxiliary shafts, kiln support bolts, petrochemical medium-temperature reactor fittings, hot air circulation valve bodies, stainless steel standard parts under repeated thermal cycles, etc.
Widely applied in thermal power boiler auxiliary parts, automotive exhaust systems, industrial heat treatment furnaces, food high-temperature sterilization equipment, petrochemical medium-temperature units, HVAC heat exchange equipment, waste incineration medium-temperature pipelines, thermal steam pipe networks and other industries.
Core Advantages Over Competitors
1. High quality stability: Full closed-loop production and online spectral inspection strictly control C, Cr, Ni, Ti with stable Ti/C ratio. Uniform segregation-free austenitic microstructure ensures negligible batch fluctuation of medium-temperature anti-sensitization, creep strength and mechanical properties for consistent mass production of high-temperature welded parts.
2. Excellent surface quality: Dedicated high-precision cold drawing & centerless grinding lines produce bars free of scale, scratches and pits with smooth uniform finish. Smooth surface reduces alternating thermal stress concentration to extend fatigue life under hot-cold cycles; secondary polishing is unnecessary for most conventional machining.
3. Ultra-high dimensional accuracy: Precision cold rolling mills and automatic online dimension detectors narrow tolerance range with tiny single-bar error and strong batch uniformity. Unified part specifications during automatic mass production raise finished yield and machining precision.
4. Rich product variety: According to market demand and customer's special requirements, customized 321 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.