Alloy Steel Plate
Alloy steel plate is flat rolled steel blended with Cr, Mo, Mn, Ni and other alloy elements, far exceeding ordinary carbon steel in strength, high-temperature stability and wear resistance. Manufactured by hot rolling, quenching & tempering. Custom thickness, width and cutting services are available, widely adopted in pressure vessels, heavy machinery, petrochemical and construction fields for high-load & harsh-environment components.
Available Grades
① A387 Gr11 Cl.2 (Cr-Mo boiler alloy plate)
Chromium-molybdenum heat-resistant alloy steel, stable under 500℃ high temperature and high pressure. Mainly used for boiler drums, heat exchangers and oil pipeline pressure vessels in power & petrochemical industries.
② A514 Grade S (Ultra-high strength quenched & tempered plate)
Premium low-alloy QT steel with tensile strength above 690MPa, excellent low-temperature impact toughness and good weldability. Ideal for heavy truck frames, offshore platform structures and high-load bridge girders.
③ 4140 / 42CrMo4 (Cr-Mo structural alloy plate)
Medium carbon alloy steel with outstanding hardenability and wear resistance after heat treatment. Suitable for gear blanks, mold base plates, hydraulic equipment and heavy machinery structural parts.
④ S355J2 (Low alloy high-strength structural plate)
Economical universal alloy plate, guaranteed -20℃ low-temperature impact performance. Widely used in building steel structures, ship hulls and general engineering load-bearing components.
⑤ S690QL (Super high-strength low-temperature alloy plate)
Yield strength ≥690MPa, stable impact toughness at -40℃. Preferred for wind tower flanges, mining equipment and mobile construction machinery requiring lightweight & high load capacity.
Product Features
- Superior mechanical strength: Higher yield & tensile strength than carbon steel, supports heavy load without deformation.
- Excellent temperature resistance: Cr-Mo grades maintain stable performance under continuous high temperature; low-alloy grades avoid brittle fracture in cold environments.
- Good machinability & weldability: Balanced alloy composition supports cutting, bending, forging and standard welding processes.
- Strong wear & fatigue resistance: Alloy grain refinement extends service life for dynamic-load working parts.
- Strict dimensional precision: Controlled rolling tolerance, customizable size to reduce secondary processing cost.
Applications
- Petrochemical & Power EquipmentCr-Mo alloy plates manufacture high-pressure boilers, heat exchangers and reaction tanks, resisting high heat & medium corrosion in oil refineries and power plants.
- Heavy Mining & Construction MachineryHigh-strength grades make excavator arms, crane beams and mining vehicle chassis, bearing repeated impact and heavy field loads.
- Offshore & Marine EngineeringLow-temperature tough alloy plates build ship hulls, offshore platform supports, adapting to seawater and cold ocean climate.
- Bridge & Building StructureS355/S690 series for bridge girders, high-rise load-bearing frames, balancing structural safety and self-weight reduction.
- Mold & Mechanical Processing Parts4140/42CrMo plates serve mold substrates, gear blanks and hydraulic valve blocks, delivering long-term wear resistance after heat treatment.
Product Advantages
- Longer service lifespan: Alloy reinforcement cuts equipment replacement frequency, lowering clients’ long-term operation costs.
- Lightweight structural design: Higher strength allows thinner plate thickness, reducing overall equipment weight and transportation expense.
- One-stop customization: Free cutting, heat treatment and surface processing, saving clients extra outsourcing processing fees.
- Stable batch consistency: Strict mill inspection & full chemical/mechanical test reports, avoiding on-site assembly failure risks.
- Wide grade coverage: Cover low-cost structural to high-temperature pressure vessel grades, matching different project budget demands.
Technical Data Table
| Parameter Unit | A387 Gr11 Cl.2 | A514 GrS | 4140 (QT) | S355J2 | S690QL |
| Tensile Strength (MPa) | 415–585 | ≥690 | ≥1080 | 470–680 | 770–940 |
| Yield Strength (MPa) | ≥205 | ≥620 | ≥930 | ≥355 | ≥690 |
| Elongation (%) | ≥22 | ≥16 | ≥12 | ≥22 | ≥14 |
| Density (g/cm³) | 7.85 | 7.85 | 7.85 | 7.85 | 7.85 |
| Low-Temp Impact Energy | ≥27J @ 20℃ | ≥34J @ -40℃ | ≥15J @ RT | ≥27J @ -20℃ | ≥30J @ -40℃ |
| Max Hardness (HB) | ≤163 | ≤250 | 300–360 | ≤225 | ≤270 |
Why Choose Us
- Professional alloy steel manufacturer with 30+ years export experience.
- Flexible MOQ: Support bulk container orders and small trial orders for project verification.
- Custom service: Custom thickness, width, length, flame cutting, plasma cutting and surface blasting as client drawings（MOQ requirement please check with sales team）
- Global logistics team: Familiar with port clearance for Southeast Asia, Middle East, Europe and America, door-to-door delivery available.
Packaging & Shipping
Packaging
- Thin plates: Wrapped with anti-rust waterproof paper + PE protective film; Medium & heavy plates: Bundled by high-tensile steel strips, fitted with corner guards to prevent edge scratch during transit.
- All bundles marked with clear shipping marks, specification labels and moisture-proof warning logos.
- Custom seaworthy wooden crates available for special fragile or precision-cut plates.
Shipping
- Container shipment: 20GP / 40HQ standard containers, goods fully fixed with steel supports to avoid shifting.
- Bulk vessel shipment for ultra-heavy large orders, cost-effective for mass engineering procurement.
- Delivery ports: Tianjin, Shanghai, Qingdao; support FOB, CFR, CIF and DDP trade terms.
- Complete export files: Commercial invoice, packing list, bill of lading, certificate of origin, MTC, ISO & CE certifications provided.
FAQ
- Q1: Can I get custom alloy steel plate sizes?
A: Yes. We provide flexible cutting services including flame cutting, plasma cutting and saw cutting. Send your drawing or required thickness/width/length for a free quotation. - Q2: What test certificates can you offer?
A: Every shipment comes with original Mill Test Certificate (MTC) covering chemical composition and full mechanical data. - Q3: How long is your production & delivery lead time?
A: Stock items ship within 3–7 working days; customized heat-treated plates take 10–18 working days. We will confirm exact schedule after order confirmation. - Q4: Do alloy steel plates rust during sea transport?
A: We adopt multi-layer anti-rust packaging including waterproof film and anti-rust paper. For long-distance ocean shipping, we add extra desiccant inside bundles to eliminate salt fog corrosion risk. - Q5: Can you support heat treatment on finished plates?
A: Yes, quenching, tempering, normalizing and annealing services are available to adjust hardness and toughness according to your working condition requirements.
