1.7335, designated as 13CrMo4-5 under EN and equivalent to ASTM A387 Grade 12 / A182 F11-F12, is a low-alloy chromium-molybdenum heat-resistant steel bar engineered for elevated-temperature service in oil refining, petrochemical processing and power generation. SHUNFU METAL supplies this grade in multiple bar and forging forms with rigorous high-temperature property certification.
This Cr-Mo low-alloy steel originates from the EN 10028-2 and EN 10273 standards as a normalized and tempered heat-resistant grade. Designed for sustained operation up to 550°C, it is the industry-standard material for refinery pressure vessels, boiler drums, heat exchangers, superheater headers, and high-temperature pipe fittings. The balanced chemistry of 0.08–0.18% carbon with 0.70–1.15% chromium and 0.40–0.60% molybdenum delivers excellent creep resistance, hydrogen attack resistance, and weldability — properties essential for long-term reliability in hot hydrogen and steam service.
At SHUNFU METAL, 1.7335 bars are melted via electric arc furnace with ladle refining and vacuum degassing to achieve ultra-low sulfur and phosphorus levels (S ≤ 0.010%, P ≤ 0.025%). Each heat is verified by optical emission spectrometry. Bars are hot-rolled or forged, then normalized at 910–940°C and tempered at 650–720°C to the ordered strength level. Ultrasonic testing per EN 10308 / ASTM A388 is performed on every bar, with full EN 10204 3.1 or 3.2 certification documenting chemical, mechanical, and NDT results.
Equivalent Grades of 1.7335
1.7335 / 13CrMo4-5 has recognized equivalents across major international standards for pressure vessel and elevated-temperature service. The closest ASTM counterpart is A387 Grade 12 (plate) and A182 F11/F12 (forgings).
| Standard | Designation | Remarks |
|---|---|---|
| DIN W-Nr. | 1.7335 | German Werkstoff number |
| EN | 13CrMo4-5 | Pressure vessel & boiler steel |
| ASTM | A387 Gr.12 / A182 F11-F12 | Plate & forging grades |
| JIS | SFVAF12 | Boiler & pressure vessel steel |
| GOST | 12ХМ / 15ХМ | Russian Cr-Mo heat-resistant grade |
| GB | 15CrMoR / 12CrMo | Chinese boiler & pressure vessel steel |
No direct AMS equivalent exists. A335 P11/P12 applies to the seamless tube product form under the same Cr-Mo family.
Oil & Gas & Petrochemical Applications
1.7335 / 13CrMo4-5 steel bars are machined, forged, and fabricated into critical high-temperature pressure boundary components for refinery, petrochemical, and power generation service where resistance to creep, hydrogen attack, and thermal fatigue is mandatory.
Boiler Drums
Pressure Vessels
Heat Exchangers
Superheater Headers
Valve Bodies
Pipe Fittings
Flanges
Turbine Fasteners
Boiler Support Rods
Separator Vessels
Pump Shafts
Spherical Tanks
Supply Range — 1.7335 Steel Bar
SHUNFU METAL maintains comprehensive inventory of 1.7335 bars in normalized and tempered condition under ISO 9001-certified quality management. All products ship with EN 10204 3.1 or 3.2 mill certificates documenting heat number, full chemical analysis, mechanical test results, and ultrasonic examination reports.
| Form | Process | Diameter / Thickness | Width | Length |
|---|---|---|---|---|
| Round Bar | Hot-Rolled | ⌀10–500 mm | — | 3000–12000 mm |
| Round Bar | Forged | ⌀100–800 mm | — | 2000–8000 mm |
| Flat Bar | Hot-Rolled | 3–150 mm | 20–610 mm | 3000–12000 mm |
| Flat Bar | Forged | 50–500 mm | 100–1200 mm | 2000–6000 mm |
Non-standard sizes, stepped shafts, forged rings (OD 200–1500 mm), discs, tube sheets, and blocks are available upon inquiry. SHUNFU METAL also offers rough machining, saw cutting, and normalizing + tempering heat treatment services per customer specification.
Chemical Composition of 1.7335
The chemical composition conforms to EN 10028-2 and EN 10273 13CrMo4-5 specifications. The chromium-molybdenum alloy design provides high-temperature oxidation resistance, creep strength, and resistance to hydrogen attack — making it the material of choice for hot hydrogen service in refinery and petrochemical plants.
| C | Si | Mn | P | S | Cr | Mo |
|---|---|---|---|---|---|---|
| 0.08–0.18 | ≤0.35 | 0.40–1.00 | ≤0.025 | ≤0.010 | 0.70–1.15 | 0.40–0.60 |
Values in weight percent (wt%). Iron (Fe) balance. Nitrogen ≤ 0.012%; Copper ≤ 0.30%. For hydrogen service, minimum Cr may be specified at 0.80%. SHUNFU METAL verifies all heats by optical emission spectrometry and reports trace elements on every certificate.
Mechanical Properties of 1.7335 / 13CrMo4-5
In the normalized and tempered (+NT) condition per EN 10273, 1.7335 delivers a well-balanced combination of room-temperature strength, ductility, and toughness alongside reliable elevated-temperature creep resistance. For thicker sections (>150 mm), quenched and tempered (+QT) delivery is available. SHUNFU METAL applies controlled normalizing at 910–940°C and tempering at 650–720°C to achieve the specified properties for each thickness category.
| Property | ≤16 mm | 16–60 mm | 60–100 mm | 100–150 mm |
|---|---|---|---|---|
| Tensile Strength (MPa) | 450–600 | 450–600 | 440–590 | 430–580 |
| Yield Strength (min, MPa) | 300 | 290 | 270 | 255 |
| Elongation (min, %) | 19 | 19 | 19 | 19 |
| Impact KV (min, J @ 20°C) | 31 | 31 | 27 | 27 |
| Hardness (HBW, typical) | ≤250 | ≤250 | ≤250 | ≤250 |
| Creep Strength (MPa @ 500°C / 100,000 h) | 137 (Rz/100000) | |||
| Heat Treatment | Normalized 910–940°C + Tempered 650–720°C |
For bars >150 mm thickness, quenched and tempered (+QT) condition applies: tensile 420–570 MPa, yield ≥245 MPa, elongation ≥19%. Elevated-temperature yield and creep data available upon request. SHUNFU METAL performs tensile, impact, and hardness testing on each heat treatment lot per EN 10273 requirements.
Need 1.7335 13CrMo4-5 Steel to the specification above?
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