Project Description
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.
Introduction to 1.7335 / 13CrMo4-5
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.
Steam generator shells
Refinery & chemical reactors
Shells, tube sheets, channels
Power boiler steam outlets
High-temp gate & globe valves
Tees, elbows, reducers, caps
Weld neck, slip-on, blind
Studs, nuts for steam turbines
Structural stays & hangers
Oil-gas-water separators
Boiler feed & process pumps
LPG & ammonia storage
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.