1.7380 (10CrMo9-10) Forged Parts | ISO 9001 Certified China Forging Manufacturer

Why Choose Our 1.7380 (10CrMo9-10) Forgings

1.7380 (10CrMo9-10) Steel: Material Science & Why It Works at High Temperature

What is 1.7380 (10CrMo9-10) Steel?

1.7380, designated 10CrMo9-10 under the European EN system and equivalent to ASTM A335 Grade P22 in the United States, is a low-alloy chromium-molybdenum pearlitic steel specifically engineered for continuous high-temperature and high-pressure service. The designation encodes its composition: the "10" denotes approximately 0.10% carbon, "Cr9" refers to the 2.0–2.5% chromium content (expressed as 9× the percentage for two-digit alloy steels in EN nomenclature), and "Mo10" indicates 0.9–1.1% molybdenum.

The alloy occupies a critical design space in the global high-temperature steel hierarchy — significantly more capable than carbon steels and low-chromium grades like 16Mo3 (1.5415), yet far more weldable and economical than the advanced 9–12% chromium martensitic steels such as P91 or P92. This balance has made it the workhorse material for power plant boilers, petrochemical reactors and oil & gas pressure components operating between 400℃ and 580℃ for over six decades.

The Metallurgical Science Behind 1.7380's High-Temperature Strength

Understanding why 10CrMo9-10 performs so well at elevated temperatures is essential for engineers specifying this material and for procurement teams evaluating whether a forging supplier truly understands what they are producing.

Chromium's role — carbide stability and oxidation resistance: The 2.0–2.5% chromium content in 1.7380 serves two critical functions simultaneously. First, chromium combines with carbon to form thermally stable alloy carbides (primarily M₇C₃ and M₂₃C₆ types). Unlike the iron carbide (Fe₃C, cementite) found in plain carbon steels, these chromium-rich carbides resist dissolution and coarsening at operating temperatures up to 580℃, preserving fine dispersion strengthening and blocking dislocation movement — the core mechanism of creep resistance. Second, chromium forms a thin, adherent Cr₂O₃-rich oxide layer on the steel surface, providing oxidation protection that extends service life without the need for coatings in most boiler and reactor environments.

Molybdenum's role — solid-solution strengthening and creep resistance: The 0.9–1.1% molybdenum is arguably the most important element in the alloy for long-term creep resistance. Molybdenum atoms, being significantly larger than iron atoms, cause substantial lattice strain in the ferritic matrix. This solid-solution strengthening effect is highly temperature-resistant and does not diminish with normal service ageing at 500–580℃. Additionally, molybdenum retards the coarsening of carbides during long-term service, maintaining the fine dispersion that anchors dislocations during creep. Field data from European thermal power plants confirm that 2.25Cr-1Mo forgings (1.7380) in steam headers retain creep rupture strengths close to their original design values after 100,000+ service hours at 550℃.

Why 580℃ is the practical service limit: Above approximately 580–590℃, two degradation mechanisms accelerate sharply. First, carbide dissolution rates increase dramatically, reducing the dispersion strengthening effect. Second, at these temperatures in certain service environments, sigma-phase (FeCr intermetallic) can begin to precipitate along grain boundaries over very long exposures, causing severe embrittlement. For these reasons, EN standards and ASME code cases define 580℃ as the upper service limit for 10CrMo9-10 in long-term pressure equipment design.

The pearlitic microstructure advantage for welding: Unlike the martensitic 9Cr steels (P91, P92) which require stringent preheat and precisely controlled post-weld heat treatment to restore toughness after martensite formation, 1.7380 transforms to a fine pearlite + bainite structure during normalization and tempering. This pearlitic microstructure is inherently less sensitive to hydrogen-induced cracking during welding, allows more forgiving preheat requirements (150–250℃ vs. 200–300℃ for P91), and accommodates minor PWHT temperature variations without the risk of re-austenitizing martensite. This metallurgical characteristic translates directly to lower fabrication risk and lower total cost for field-welded assemblies.

Key Performance Advantages in Forged Form

• Superior creep resistance vs. plain carbon steels: At 550℃, the 100,000-hour creep rupture strength of 1.7380 (approximately 60 MPa) is 5–6× higher than Grade P1 (0.5Mo) and 3× higher than Grade P11 (1.25Cr-0.5Mo), enabling longer intervals between maintenance shutdowns
• High-temperature oxidation resistance up to 580℃: The Cr₂O₃ passive layer limits scale growth to less than 0.2mm after 50,000 hours at 550℃ in steam — sufficient for most power plant and reactor design margins
• Excellent weldability with manageable PWHT: Carbon equivalent (CEV) typically in the range 0.60–0.75, requiring preheating of 150–250℃; PWHT at 720–750℃ restores full toughness and stress-relief without complex post-heating hold sequences
• Outstanding hardenability in large cross-sections: The Cr+Mo combination ensures through-hardening in quench-and-temper treatment even in sections exceeding 500mm diameter — critical for large forged valve bodies, reactor shells and turbine shafts where centerline properties are as important as surface properties
• Proven long-term hydrogen attack resistance: The Nelson Curve for 2.25Cr-1Mo steel demonstrates resistance to hydrogen attack at partial pressures up to 10 MPa and temperatures up to 450℃, making it suitable for hydrocracking reactors and hydrotreating service
• Excellent machinability in the normalized & tempered condition: Hardness range of 140–180 HB allows efficient CNC machining with standard tooling, reducing finished component lead times and costs

1.7380 (10CrMo9-10) International Equivalents — Full Cross-Reference Guide

1.7380 / 10CrMo9-10 is one of the most globally harmonized engineering steels, with closely matching equivalents across all major industrial standards. However, there are important differences in heat treatment conditions, impact test requirements, and applicable product forms that procurement engineers must understand before substituting one designation for another.

1.7380 vs. Alternative High-Temperature Steels — Engineer's Selection Guide

Selecting the correct chrome-molybdenum steel grade is one of the most consequential material decisions in high-temperature pressure equipment design. Choosing the wrong grade can result in either overdesign and unnecessary cost, or unsafe service conditions. Based on 25+ years of producing forgings for global clients, our technical team has compiled the following practical selection matrix.

When to Specify 1.7380 Instead of P91

Many engineers default to P91 (X10CrMoVNb9-1) because of its higher strength numbers, but in applications where the operating temperature is below 580℃, 1.7380 is frequently the superior engineering choice for three reasons. First, P91 requires stringent PWHT control — the tempering window is narrow (750–780℃) and deviation by even ±15℃ can leave the weld heat-affected zone under-tempered, creating embrittlement risk in service. Second, Type IV cracking at the outer edge of the HAZ is a well-documented failure mode in P91 welded joints under creep conditions, a failure mode absent in 1.7380 pearlitic steels. Third, P91 requires 100% PWHT after any welding, including repair welds, while 1.7380 permits more flexible repair procedures. In our experience supplying forgings for German and UK power plants, procurement engineers transitioning from supercritical to advanced ultra-supercritical service often specify 1.7380 for auxiliary steam piping and headers even on P91 main steam projects, precisely to avoid the PWHT complexity.

When to Step Up from 13CrMo4-5 to 1.7380

13CrMo4-5 (1.7335, equivalent to ASTM A335 P11) is a reasonable choice for service up to about 540–550℃. When design temperature exceeds 545℃, or when the component operates continuously at high stress levels (> 100 MPa), or when hydrogen partial pressure exceeds approximately 4 MPa at 400℃, the additional Cr and Mo content of 1.7380 becomes technically necessary rather than merely desirable. We frequently assist clients in upgrading existing 1.7335 designs to 1.7380 when plant operating conditions are revised upward after initial commissioning.

Why Forged 1.7380 Outperforms Cast 10CrMo9-10 in High-Temperature Service

When engineers evaluate 10CrMo9-10 components, they sometimes ask whether casting can deliver equivalent performance to forging at lower cost. For ambient-temperature structural applications in low-stress environments, casting may be acceptable. For high-temperature pressure equipment subject to sustained stress, thermal cycling and creep, the gap in performance is significant and the choice of forging is not merely a preference but a structural engineering requirement.

Custom 1.7380 (10CrMo9-10) Forged Products We Supply

We produce a comprehensive range of custom 10CrMo9-10 forged components, with single piece weight from 30KGS to 30,000KGS. Every product is manufactured to your drawing, heat treated to EN or ASTM requirements, and fully tested before shipment:

Forging Size & Tolerance Capabilities

View our full product catalog: All Forged Products | All Alloy Steel Materials

1.7380 (10CrMo9-10) Compliance Standards & Chemical Composition

Global Compliance Standards We Certify To

• EN 10028-2: Flat products for pressure purposes — defines chemistry, mechanical properties and test requirements for plate and sheet; our forgings are certified equivalent per mutual recognition with EN 10250-2
• EN 10216-2: Seamless steel tubes for pressure purposes — applicable for hollow forgings and forged tube blanks
• EN 10253-2: Butt-welding pipe fittings for high-temperature pressure service
• EN 10273: Hot rolled steel bars for pressure purposes — directly applicable to all our bar forgings and machined blanks
• EN 10228-3: NDT of steel forgings, Part 3 — UT for ferritic/martensitic forgings; we certify to quality class S3/E3 as standard, S2/E2 or S1/E1 on request
• PED 2014/68/EU (EU Pressure Equipment Directive): Our products are manufactured to the EN harmonized standards (EN 10028-2, EN 10273, EN 10228-3) that underpin PED compliance. EN 10204 3.2 MTC with third-party inspection body witnessing is available to support your EU-side PED conformity assessment process. Note: PED conformity assessment and CE marking are conducted by the EU importer/manufacturer of the finished pressure equipment, not by the raw material forging supplier
• API 6A (Wellhead and Christmas Tree Equipment): Products can be manufactured to meet API 6A material chemistry, mechanical property and dimensional requirements. We can provide full material test documentation consistent with API 6A material qualification. Note: API Monogram licensing is held by the finished equipment manufacturer; we supply API 6A-compatible forgings as a material subcontractor
• ASME Section VIII Div. 1 / Div. 2: For US-market pressure vessels and heat exchangers, we certify to ASME Code with A182 F22 Cl. 3 or A336 F22 chemistry and mechanical requirements
• DIN 17175: Legacy standard for seamless steel tubes at elevated temperatures — still specified by some retrofit and legacy power plant projects
• NACE MR0175 / ISO 15156: Sulphide stress cracking resistance material specification for sour oil & gas service — our 1.7380 forgings can be heat treated and documented to meet NACE MR0175 hardness and material requirements. NACE MR0175 is a material specification, not a company certification; compliance is demonstrated through hardness test results documented in the MTC

Chemical Composition — EN 10028-2 Smelt Analysis

Heat Treatment & Mechanical Properties — Complete Technical Data

Standard Heat Treatment Process

• Normalizing: Austenitizing at 930–960℃, air cooling — used for stress relieving rough forgings before final heat treatment; produces a fine pearlite-bainite microstructure with moderate strength
• Full Annealing: Austenitizing at 870–900℃, slow furnace cooling at ≤ 50℃/hour to below 600℃ — produces maximum softness for machining; not suitable for final delivery condition in most pressure equipment applications
• Isothermal Annealing: Austenitize at 860–890℃, cool to 680–720℃ and hold 4–8 hours, air cool — more uniform softness than full annealing, preferred for large sections where furnace cooling rate is difficult to control
• Quenching + Tempering (Q+T) — Recommended for all pressure equipment: Austenitize at 920–950℃, oil quench; temper at 730–760℃ with minimum hold time = (wall thickness in mm) ÷ 25 hours, minimum 1 hour, then air cool. Achieves the optimal combination of strength, toughness and creep resistance specified in EN 10028-2
• Post-Weld Heat Treatment (PWHT): 720–750℃, minimum hold time 2 minutes per mm of weld throat thickness, minimum 30 minutes total. PWHT is mandatory for 1.7380 welded assemblies operating above 300℃ or with wall thickness exceeding 12mm

Room Temperature Mechanical Properties (Wall Thickness ≤ 60mm, Q+T Condition)

Thickness Effect on Mechanical Properties

High Temperature Proof Strength & Creep Rupture Data

Welding Performance Guide — Practical Parameters

1.7380 (10CrMo9-10) has good weldability with proper process control. Below are the parameters our engineering team provides to welding engineers receiving our forgings:

• Recommended welding processes: SMAW (111), SAW (12), GTAW/TIG (141), GMAW/MIG (131/135), electroslag welding (72) for large-section joins
• Preheat temperature: 150–250℃ for wall thickness ≤ 25mm; 200–250℃ for 25–60mm; 250℃ minimum for sections > 60mm. Preheat must extend 75mm each side of the joint and be maintained throughout welding
• Interpass temperature: ≤ 300℃ maximum — exceeding this can cause austenite formation in the HAZ and introduce untempered martensite on subsequent cooling
• PWHT temperature: 720–750℃. This window is critical: below 720℃, residual stress relief is incomplete and carbide precipitation is insufficient; above 760℃, risk of partial re-austenitization with associated microstructural damage
• PWHT hold time: 2 min/mm of maximum weld throat thickness, minimum 30 minutes. For wall thicknesses above 100mm, calculate hold time with thermal gradient modelling to ensure center temperature reaches the target range
• Consumable selection: ER90S-B3 / ER90S-G (GTAW wire), E9015-B3 / E9018-B3 (SMAW electrode), EB3 submerged arc wire with compatible basic flux. Hydrogen-controlled (low-hydrogen) consumables are mandatory — E9015 is preferred over E9010 for hydrogen content control
• Post-heat before PWHT: Where PWHT is delayed (common in field erection), maintain 250℃ post-heat for 1 hour after welding completion to allow hydrogen to diffuse out before the joint cools — this prevents hydrogen-induced cold cracking in the HAZ

Procurement Engineer's Guide to Ordering 1.7380 (10CrMo9-10) Forgings

Based on our experience processing thousands of purchase orders from engineering procurement teams across Europe, the Middle East and North America, we have compiled the most common specification issues, documentation requirements, and practical guidance that saves time and prevents costly revisions during order processing.

What to Include in Your Technical Specification

A complete technical specification for 1.7380 forgings should include the following, in order of importance:

1. Applicable standard and grade: State explicitly — e.g. "EN 10028-2 Grade 10CrMo9-10 (1.7380)" or "ASTM A182 Grade F22 Class 3." Do not simply write "2.25Cr-1Mo steel" without a standard reference, as this creates ambiguity around heat treatment condition and test requirements
2. Delivery condition (heat treatment): "Q+T (quenched and tempered)" should be specified unless there is a specific reason to request annealed or normalized. Q+T is the right condition for all pressure equipment applications above 400 °C
3. NDT requirements: State UT class per EN 10228-3 (S1/E1, S2/E2 or S3/E3). If not specified, we default to S3/E3, which is suitable for most applications. If MT or PT is required on machined surfaces, state this explicitly. If UT mapping with full scan coverage report is required, note this in the specification
4. MTC type: Specify EN 10204 3.1 or 3.2. For PED-regulated applications, 3.2 (witnessed by independent inspection body) is mandatory and should be confirmed with your notified body before ordering
5. Third-party inspection: Specify inspector (BV, SGS, TUV, Lloyds, DNV, RINA etc.) if required, and the inspection scope (material review, heat treatment witnessing, mechanical test witnessing, dimensional inspection, PMI, final acceptance)
6. Dimensional tolerances: Specify machining allowances, surface finish (Ra or Rz), and critical tolerances for bores, ODs and faces. We recommend providing a full 2D engineering drawing with GD&T annotations rather than a text description
7. Impact test requirements: State test temperature if different from standard 20℃, minimum energy (J) if different from EN minimum, number of specimens, and whether longitudinal, transverse or both are required
8. Marking requirements: Specify how you require parts to be marked — heat number, material grade, heat treatment condition, part number, weight, and whether low-stress stamp, vibro-engraving or paint stencil is acceptable for your application

How to Read a 1.7380 Mill Test Certificate (MTC)

Common Specification Mistakes That Cause Delays

25-Year Manufacturer's Insights: How We Prevent the 5 Most Common 1.7380 Forging Defects

In over 25 years of producing 10CrMo9-10 forgings for global clients, our quality team has investigated and resolved hundreds of nonconformance reports from both internal inspection and client feedback. The following are the five most common defects that arise in 1.7380 forgings from inadequate production control — and the specific preventive measures we have built into our standard process to eliminate them.

Defect 1: Coarse-Grain Microstructure from Over-Temperature Soaking

Defect 2: Internal Hydrogen Flakes from Rapid Post-Forge Cooling

Defect 3: Decarburization from Uncontrolled Heat Treatment Atmosphere

Defect 4: Segregation in Large-Section Forgings

Defect 5: Inadequate Forging Ratio Leading to Residual As-Cast Structure

Full-Process Quality Control & Inspection

Our quality management system for 1.7380 (10CrMo9-10) forgings is built on a principle that has guided us since 1997: a defect caught internally is a learning opportunity; a defect delivered to a client is a failure of the entire system. Every stage of the process has defined hold points that require documented sign-off before work proceeds.

Manufacturing Process Flow with Quality Hold Points

Full Inspection Items We Provide

• Non-Destructive Testing (NDT): Ultrasonic Testing (UT) per EN 10228-3 class S3/E3, Magnetic Particle Testing (MT) per EN 10228-1, Penetrant Testing (PT) per EN 10228-2, Radiographic Testing (RT) per EN 10228-4 on specific geometries
• Mechanical Properties Testing: Tensile test (Rm, ReH, Rp0.2, A5), Charpy impact (20℃ standard, other temperatures on request), Brinell hardness (HBW), high temperature proof strength test (on request)
• Chemical Analysis: Optical emission spectrometry (OES) for all elements, carbon-sulfur combustion analysis, Positive Material Identification (PMI) by XRF on every individual forging piece
• Metallographic Inspection: Grain size rating per ASTM E112, inclusion rating per EN 10247 / ASTM E45, decarburization depth per EN ISO 3887, microstructure classification
• Dimensional Inspection: CMM three-coordinate measurement, bore roundness, OD concentricity, flatness, perpendicularity per GD&T as specified; full dimensional report provided
• Pressure Testing: Hydrostatic pressure test, air seat test and gas tightness test on closed-form components (valve bodies, pressure vessel sections) as required by design standard
• High Temperature Creep Test: Performed in our in-house elevated temperature testing laboratory; 10,000-hour extrapolation from 1,000-hour test data on request for critical applications

10CrMo9-10 (1.7380) Forgings — Global Project Reference Cases

The following cases represent actual projects completed by our team. Technical parameters are provided as illustrative reference data for engineers evaluating our capabilities against their specific project requirements.

Case 1 | Power Generation | 660MW Supercritical Boiler Project, Germany

Case 2 | Nuclear Power | Generation III Reactor Coolant System, China

Case 3 | Oil & Gas | Sour Gas Field Wellhead Equipment, Saudi Arabia

Case 4 | Petrochemical | Hydrocracking Reactor Project, Thailand

What Our Global Clients Say

Frequently Asked Questions — 1.7380 (10CrMo9-10) Forgings