1. Executive Summary
EN-GJS-400-15 is a widely used grade of ductile (գնդաձև գրաֆիտ) չուգուն սահմանված եվրոպական EN-ով 1563 ստանդարտ.
A balanced combination of moderate tensile strength, բարձր ճկունություն, Լավ կոշտություն, and excellent castability characterizes it.
With a minimum tensile strength of 400 MPa and minimum elongation of 15%, this grade is particularly suitable for components that require reliable mechanical performance, resistance to impact and vibration, and cost-effective production in complex shapes.
EN-GJS-400-15 occupies an important position between grey cast iron and higher-strength ductile irons or steels, making it a preferred choice in fluid handling, ավտոմոբիլային, մեքենաներ, and general engineering applications.
2. What is EN-GJS-400-15 Ductile Iron
Ծորակ երկաթ is a cast iron in which the graphite is present in a spheroidal (նոդուլյար) form rather than as flakes.
This graphite morphology is achieved through controlled treatment of molten iron with magnesium or magnesium-based alloys.
The spherical graphite particles significantly reduce stress concentration and crack initiation, resulting in much higher strength and ductility compared with grey cast iron.
EN-GJS-400-15 represents a ferritic or ferritic–pearlitic ductile iron grade designed to offer good elongation and toughness while maintaining sufficient strength for structural and pressure-bearing components.
It is often selected when castability and mechanical reliability are required without moving to more expensive steel forgings.
Designation and Standard
- EN-GJS: European designation for spheroidal graphite cast iron
- 400: Minimum tensile strength in MPa
- 15: Minimum elongation at fracture in percent
The grade is specified in Մեջ 1563 – Spheroidal Graphite Cast Irons. Unlike some material standards that prescribe exact chemical compositions, Մեջ 1563 defines grades primarily by mechanical properties and microstructural requirements.
This allows foundries flexibility in alloy design and processing while ensuring consistent performance for end users.
3. Standard Chemical Composition Range
EN-GJS-400-15 does not have a fixed chemical composition; փոխարեն, foundries adjust chemistry to meet mechanical and microstructural requirements.
Typical composition ranges used in industrial practice are:
| Տարր | Բնորոշ տիրույթ (wt. %) | Գործառույթ |
| Ածխածնային (Գ) | 3.2 Մի քիչ 3.8 | Խթանում է գրաֆիտի ձեւավորումը, բարելավում է կուտելիությունը |
| Սիլիկոն (Մի քանազոր) | 2.2 Մի քիչ 2.8 | Ամրապնդում է Ferrite- ը, promotes graphite spheroidization |
| Մանգան (Ժլատ) | 0.1 Մի քիչ 0.3 | Controls pearlite formation |
| Ֆոսֆոր (Իմաստ) | ≤ 0.05 | Kept low to avoid brittleness |
| Ծծումբ (Ծուռ) | ≤ 0.02 | Strictly controlled for nodularity |
| Մագնեզիում (Մգ) | 0.03 Մի քիչ 0.06 (residual) | Essential for spheroidal graphite formation |
4. Mechanical Properties and Material Performance — EN-GJS-400-15
Տիպիկ մեխանիկական հատկություններ (representative ranges)
The values below are representative of commercially produced EN-GJS-400-15 castings in the as-cast (and normally stress-relieved or lightly thermal-treated) պետություն.
Actual values depend on foundry practice, Բաժնի հաստությունը, heat treatment and inspection acceptance criteria.
| Սեփականություն | Բնորոշ / անվանական | Բնորոշ տիրույթ (practical) |
| Առավելագույն առաձգական ուժ, Ժլատ | ≈ 400 MPA | 370 Մի քիչ 430 MPA |
| 0.2% proof or yield (Մոտավոր:) | ~250–280 MPa | 230 Մի քիչ 300 MPA |
| Elongation at fracture, Էունք (%) | ≥ 15 % (grade minimum) | 15 Մի քիչ 22 % |
| Յանգի մոդուլը, Եփ | ≈ 165 Gpa | 155 Մի քիչ 175 Gpa |
| Poisson’s ratio, ն | ≈ 0.27–0.29 | 0.26 Մի քիչ 0.30 |
| Բրինելի կարծրություն, Ժապավենի | 150 (բնորոշ) | 130 Մի քիչ 230 Ժապավենի (matrix dependent) |
| Խտություն | ≈ 7.15 g · cm⁻³ | 7.05 Մի քիչ 7.25 g · cm⁻³ |
| Սեղմիչ ուժ (Մոտավոր:) | սովորաբար > Ժլատ | ~700 – 1200 MPA (dependant on matrix) |
| Կոտրվածքային կոշտություն, K_ic (Արեւելք:) | ≈ 40 Մի քիչ 70 Mpa · √ (typical ferritic/mixed) | 30 Մի քիչ 80 Mpa · √ (strongly matrix & quality dependent) |
| Fatigue endurance (unnotched, R = -1, fully reversed) | conservative: ~0.3–0.5·Rm | ~ 120 – 200 MPA (depends on finish, թերություններ) |
| Ջերմային ընդարձակման գործակիցը, էունք | ≈ 11.0 × 10⁻⁶ /K | 10.5 Մի քիչ 12.0 × 10⁻⁶ /K |
| Mal երմային հաղորդունակություն | ≈ 35 Մի քիչ 55 W·m⁻1·K-1 | 30 Մի քիչ 60 W·m⁻1·K-1 |
| Հատուկ ջերմություն | ≈ 450 J·kg-1·K-1 | 420 Մի քիչ 480 J·kg-1·K-1 |
Key Performance Characteristics and Mechanisms
Բարձր ճկունություն եւ կոշտություն
EN-GJS-400-15 is typically supplied with a ferritic or ferritic–pearlitic matrix and spheroidal graphite.
The ferritic matrix provides strong plastic deformation capability, while spherical graphite minimizes stress concentration.
Արդյունքում, standard castings achieve elongation of 15–20%, enabling the material to absorb impact loads and tolerate overload conditions without brittle failure. This makes it well suited for dynamically loaded and pressure-bearing components.
Moderate strength with favorable specific strength
The nominal tensile strength of EN-GJS-400-15 is ≈400 MPa, with typical production results in the 370–430 MPa range and occasional values approaching ≈450 MPa under optimized conditions.
This represents approximately 1.5–2 times the strength of common grey cast iron (օր., GG25), while remaining below medium-carbon steels.
Due to a density comparable to steel, է specific strength is similar to carbon steel, but casting-based manufacturing commonly delivers 20–40% lower total part cost, մասնավորապես բարդ երկրաչափությունների համար.
Լավ մեքենայականություն
With typical hardness levels of ~130–180 HB, EN-GJS-400-15 machines efficiently.
Spheroidal graphite reduces cutting forces and tool wear, supporting higher cutting speeds and stable tool life.
Արդյունաբերական պրակտիկայում, machining productivity is often 20–30% higher than for grey cast iron. Surface finishes of ՀՀ 3.2-6.3 մկմ are readily achievable in series production.
Low-temperature performance
EN-GJS-400-15 retains useful toughness at sub-zero temperatures. Մոտ -20 ° C, impact energy values of ≥20 J are commonly achieved in well-controlled castings, significantly outperforming grey cast iron.
For lower-temperature service (ներքեւից -40 ° C), improved toughness can be obtained through stricter phosphorus control (≤0.04 wt%) and moderate nickel alloying (≈0.5–1.0 wt%), enabling impact energies of ≥25 J, subject to qualification testing.
Influence of Heat Treatment on Mechanical Properties
EN-GJS-400-15 is mainly used in the cast state, but targeted heat treatment can further optimize its performance:
- Անողորմ (Ferritizing Annealing): Conducted at 850–900℃ for 2–3h, followed by furnace cooling (≤5℃/min).
This process converts residual pearlite into ferrite, increasing elongation by 5–10% and impact energy by 15–20%, suitable for components requiring ultra-high ductility (օր., pressure pipes). - Սթրեսի ռելիեֆի օծանելիք: Conducted at 550–600℃ for 3–4h, որին հաջորդում է օդի սառեցում.
Eliminates residual stress caused by uneven cooling during casting, reducing deformation during machining by 30–40%, critical for precision components (օր., automotive hubs). - Նորմալացնող: Conducted at 900–950℃ for 1–2h, որին հաջորդում է օդի սառեցում. Increases pearlite content to 15–20%, improving tensile strength to 450–500MPa, but reducing elongation to 10–12%. Used for components requiring higher strength but lower ductility requirements.
5. Production and process control (Ձուլման պրակտիկա)
Melting and nodulizing
- Charge and melt chemistry control. Consistent base chemistry is achieved by controlling the charge mix (գրություն, խոզի երկաթ, ferroalloys) and maintaining strict limits on sulfur, phosphorus and silicon.
Հալեցնում մաքրությունը, oxygen control and accurate additions are prerequisites for predictable nodularity and matrix control. - Nodulizing practice. Spheroidal graphite is produced by a controlled magnesium (or Mg + rare-earth) բուժում. Common methods include in-melt additions and ladle dosing.
Key process variables are nodulizer dosage, հալվել ջերմաստիճանը, stirring/agitation and the time interval between treatment and pour.
Improper dosing or excessive hold time produces degenerate graphite shapes (pearlitic/chunky graphite) that degrade ductility and fatigue resistance. - Inoculation and modification. Inoculants (Fe–Si based) are used to promote uniform graphite nucleation and stabilize the matrix.
Inoculation level and timing are adjusted by section size and expected cooling rate to achieve target ferrite/pearlite balance.
Casting methods and section-size effects
- Typical processes. EN-GJS-400-15 is manufactured by conventional sand casting, shell moulding, ներդրում/precision casting and centrifugal processes as required by part geometry and quantity.
Each route requires tailored thermal control and gating design to avoid defects. - Section thickness influence. Cooling rate strongly affects matrix fraction: thick sections tend toward ferrite, thin sections toward pearlite.
Foundries compensate with inoculation strategy, Gating դիզայն, chills and targeted post-cast thermal treatment where uniform properties are required. Designers should avoid extreme section variation within the same casting.
Process control and quality assurance
- Primary production metrics. Control and document: nodularity percentage, graphite size distribution, ferrite/pearlite fraction, tensile Rm and elongation, hardness mapping, and chemical composition for each heat.
- Թերի հսկողություն. Implement gating/riser design, հալեցնում մաքրությունը, and pouring practice to minimize shrinkage, porosity and inclusions. Employ filtration and degassing where geometry or service requires high integrity.
- Inspection regime. Routine checks include tensile and hardness tests, metallographic samples (նոդլութականություն, matrix fraction) and chemical analysis.
For critical parts add NDT (ռենտգերոգրաֆիկ, ուլտրաձայնային, or CT) and if necessary pressure/leak tests.
Define acceptance criteria tied to the component’s function (օր., maximum allowable porosity, minimum nodularity).
6. Կեղծում, repair and weldability
General considerations
- Ductile iron weldability is սահմանափակ relative to steels: high carbon equivalent in the heat-affected zone (ՀԱԶ), residual stresses and potential formation of hard martensitic zones create a risk of cracking if unsuitable procedures are used.
Treat welding as a qualified repair technique rather than routine fabrication.
Recommended repair welding approach
- Preheat and interpass control. Typical preheat ranges are 150-300 ° C depending on section size and geometry; maintain interpass temperatures below specified upper limits (սովորաբար < 300-350 ° C) to control cooling rate and avoid hard microstructures.
Adjust temperatures based on part mass and restraint. - Filler metal selection. Use nickel-based or specially formulated cast-iron/Fe–Ni consumables for best ductility and reduced cracking tendency.
These fillers tolerate mismatches and produce a more ductile weld metal and HAZ. Avoid plain low-hydrogen steel rods. - Welding processes. Manual metal arc welding with appropriate electrodes, TIG (GTAW) with nickel filler, and emerging methods (լազերային, induction-assisted, hybrid processes) are all used successfully when procedures are qualified.
Local preheating using induction is effective for large/complex parts. - Հետադարձ եռապատկերի բուժում. Where required, perform stress relief or tempering (commonly in the range 400-600 ° C) to reduce residual stresses and temper any hard martensite in the HAZ.
The exact cycle must be qualified to avoid over-softening or dimensional distortion. - Qualification and testing. Every weld procedure should be qualified on representative coupons and include mechanical testing (առաձգական, թեքում), hardness surveys across weld and HAZ, and appropriate NDT (penetrant, radiography or ultrasonic).
Alternatives to fusion welding
- For many repair cases consider: mechanical repair (bolted sleeves, սեղմում), metal stitching/plugging, պղծող, սոսինձի միացում, or use of repair inserts and sleeving.
These options often reduce risk and preserve base-metal properties.
7. Դիզայն, machining and surface treatment recommendations
Design guidelines
- Geometry and transitions. Use smooth transitions and generous fillets: avoid sharp corners and abrupt thickness changes that concentrate stress at nodules.
As a practical rule, choose fillet radii at least 1.5× the nominal wall thickness նվազագույնը ~3 mm for small sections. - Wall-thickness control. Design for uniform wall thickness where possible. For sand casting, typical minimum practical wall thicknesses for ductile iron are 4-6 մմ depending on tooling and casting method; adjust for structural duty and service requirements.
- Riser and gating design. Specify gating and feeding to minimize shrinkage in critical areas; include chills or local increases in section where required to control microstructure.
Machining guidance
- Tooling and geometry. Use carbide inserts with appropriate grades for interrupted cuts and roughing; positive rakes and chip breakers improve chip control.
Ground or coated carbide is preferred where pearlite content increases. - Cutting parameters. Select cutting speeds and feeds based on hardness and matrix; treat EN-GJS-400-15 like an alloy steel of comparable HB.
Use rigid machine setups, efficient coolant, and chip control to avoid chatter and surface damage. - Dimensional tolerances and finishes. Tight tolerances are achievable with proper stress-relief (see heat treatment).
Typical machined surface finishes in production can reach ՀՀ 3.2-6.3 մկմ; specify finish class and inspection points for fatigue-sensitive zones. - Աղավաղման վերահսկում. If close tolerances are required, include stress-relief anneal in the process plan and sequence roughing/finish passes to minimize distortion.
Surface protection and wear treatments
- Corrosion protection. Use paints, Epoxy ծածկույթներ, Fusion- կապված էպոքսիդ (for pipe internals), or lining systems (cement mortar, polymeric linings) depending on fluid chemistry and service temperature.
Consider cathodic protection for buried or marine applications. - Հագուստի դիմադրություն. Apply thermal spray (Հավալ), hardfacing weld overlays or local induction hardening on high-wear zones.
Հնարավորության դեպքում, design replaceable wear inserts or hardened sleeves to simplify maintenance. Validate adhesion and HAZ effects on prototype pieces. - Fatigue enhancement. For high-cycle components specify surface finishing (grinding/polishing), shot peening to induce compressive surface stresses, and removal of casting skin at critical fillets to eliminate surface defects.
8. Typical Applications of EN-GJS-400-15 Ductile Iron
EN-GJS-400-15 is a versatile cast material that combines good ductility (A ≥ 15%), չափավոր առաձգական ուժ (nominal ≈ 400 MPA), and favorable castability and machinability.
The combination makes it attractive across a broad set of industries.
Fluid-handling and hydraulic equipment
Common parts: պոմպի պատյաններ, Փական մարմիններ, եզրեր, impeller housings, pump covers, control-valve components.
Why EN-GJS-400-15: good pressure containment and toughness, excellent castability for complex internal cores, good machinability for sealing surfaces and ports.
Պոմպ, compressor and valve trim components
Common parts: valve bonnets, մղիչի պատյաններ, gearbox housings for pumps.
Why EN-GJS-400-15: combination of impact resistance and machinability for precision mating surfaces and threaded features; resilience to transient hydraulic shocks.
Power transmission and gearbox housings
Common parts: Հաղորդման տուփի տներ, Դիֆերենցիալ կրիչներ, bell housings, փոխանցման փակագծեր.
Why EN-GJS-400-15: stiffness for accurate bearing alignment (E ≈ 160–170 GPa), damping properties reduce noise/vibration, and integral casting reduces assembly count. Economical for medium-duty driveline applications.
Automotive suspension, steering and structural components
Common parts: ծղան, control-arm housings (in some vehicle classes), Փակագծեր, եզրեր.
Why EN-GJS-400-15: good toughness and energy absorption in impact or overload events, improved fatigue behavior vs grey iron, cost advantages for complex geometries.
Agricultural and construction equipment
Common parts: linkage housings, housings for hydraulic motors, շարժակների, coupling flanges, frame brackets.
Why EN-GJS-400-15: robust to shock loading and abrasive environments; cast near-net shapes reduce welding/assembly.
Machine frames, supports and general industrial castings
Common parts: Մեքենայի հիմքերը, pump mounts, compressor frames, gearbox frames.
Why EN-GJS-400-15: favorable damping (reduces transmitted vibration), dimensional stability after stress relief, easily machined mounting features.
Խողովակների կցամասեր, manhole covers and municipal hardware
Common parts: կցամասեր, շիվներ, արմունկներ, flanged components, Մանուշակագույն ծածկոցներ, street furniture.
Why EN-GJS-400-15: ամրություն, Ազդեցության դիմադրություն, good castability for shapes with varying wall thicknesses, and economy in medium to large volumes.
Երկաթուղի, marine and off-highway components
Common parts: միացումներ, փակագիծ, housings for onboard pumps and auxiliary equipment.
Why EN-GJS-400-15: toughness in impact environments, acceptable corrosion resistance with coatings, and good fatigue performance when produced to high quality.
Bearing housings, bushings and structural supports
Common parts: housing bodies, bearing carriers, pillow blocks (where white-metallurgy inserts or liners are used).
Why EN-GJS-400-15: supports precise bores when stabilized by stress relief; good compressive and bearing capacity.
Wear and abrasion-resistant components (with surface treatments)
Common parts: հագնել ափսեներ, crusher housings (գծերով), impeller shrouds (lined).
Why EN-GJS-400-15: base casting gives toughness and structural support; wear life is provided by overlays, ծածկոցներ, or local induction hardening. This approach is more economical than making the entire part from a hard steel.
Prototype and small-volume precision castings
Common parts: bespoke housings, prototypes requiring close dimensional control, ցածր ծավալով արտադրություն.
Why EN-GJS-400-15: ability to produce intricate geometries with good surface finish and reduced machining; predictable material response aids rapid prototyping to production transition.
9. Commonly used international equivalent standards for EN-GJS-400-15
| Շրջան / Standard system | Common designation (համարժեք) | Typical reference standard | Nominal tensile (Մոտավոր:) | Nominal elongation (Մոտավոր:) | Նշումներ / ուղղորդում |
| Եվրոպան (original) | En-gjs-400-15 | Մեջ 1563 | 400 MPA (թեփ) | 15 % (թեփ) | Baseline European grade; often specified by EN designation and material number (5.3106). |
| Դեպի (historic) | GGG40 | Դեպի (ժառանգություն) | ~ 400 mpa | ~ 15 % | Older German designation frequently mapped to EN-GJS-400-15; check supplier certificate for confirmation. |
| ISO | GJS-400-15 | ISO 1083 (spheroidal graphite irons) | ~ 400 mpa | ~ 15 % | ISO naming aligns closely with EN naming; use ISO/EN text to confirm microstructure acceptance. |
| ASTM (Ամերիկա) — closest by elongation | A536 Grade 60-40-18 (Մոտավոր:) | ASTM A536 | 414 MPA (60 ksi) | ~ 18 % | Closer in elongation than some ASTM grades; UTS slightly higher than 400 MPA. Use when elongation is priority. |
ASTM (Ամերիկա) — closest by tensile |
A536 Grade 65-45-12 (Մոտավոր:) | ASTM A536 | ~448 MPa (65 ksi) | 12 % | Closer in tensile strength but lower elongation (12%). Not a direct one-to-one match — choose by mechanical tradeoff. |
| Շապիկ (PRC) | QT400-15 | Գբ / տ (nodular cast iron series) | ~ 400 mpa | ~ 15 % | Common Chinese designation for the same performance band. Confirm national standard clause and certificate. |
| Typical commercial notation | 5.3106 | Եվրոպական նյութի համարը | ~ 400 mpa | ~ 15 % | Material number often used in procurement and supplier documentation to avoid ambiguity. |
10. Կայունություն, recyclability and cost considerations
- Վերամշակելիություն: ductile iron is highly recyclable within standard ferrous recycling streams.
Foundry practice commonly incorporates significant scrap fractions, reducing embodied energy on a per-part basis relative to primary metallurgy. - Կյանքի ցիկլի արժեքը: բարդ ձևերի համար, cast EN-GJS-400-15 often offers lower total part cost than multi-piece welded steel assemblies or forged components when accounting for near-net geometry, machining allowances and part consolidation.
Consider maintenance, reparability and coating life when performing life-cycle cost comparisons.
11. Comparison with similar materials
| Սեփականություն / Նյութական | En-gjs-400-15 (ծորակ երկաթ) | En-gjs-500-7 (high-strength GJS) | Adi (Austempered Ductile Iron) | Միջին ածխածնային պողպատ (C45 / 1045) | ASTM A536 (65-45-12) |
| Typical tensile Rm (MPA) | ≈ 370–430 | ≈ 450–550 | ≈ 500–1,400 (Դասարանի կախված) | ≈ 600–750 | ≈ 420–480 |
| Typical elongation A (%) | 15-20 | ≈ 6–10 | ≈ 3–12 | ≈ 10–16 | ≈ 12 |
| Typical Brinell HB | 130-180 | 160-240 | 200-500 | 160-220 | 150-220 |
| Յանգի մոդուլը (Gpa) | 160-170 | 160-170 | 160-170 | 200-210 | 160-170 |
| Մեքենայություններ (ազգական) | Good — graphite aids chip breaking; carbide tooling recommended | Fair — higher pearlite increases tool wear | Lower — much harder, requires robust tooling | Good — conventional machining practice | Good — similar to EN-GJS family |
Եռակցման հնարավորություն (ազգական) |
Moderate — repair welding requires qualified procedures & Ni fillers | Moderate — similar constraints; procedure qualification required | Poor–Moderate — welding typically avoided | Good — routine welding with standard consumables | Moderate — qualified welding required |
| Բնորոշ ծրագրեր | Պոմպ & Փական մարմիններ, տներ, Մեքենաների շրջանակներ, ծղան | Heavier-duty housings, Gears, Բարձր սթրեսի բաղադրիչներ | Բարձր հագնում շարժակները, լիսեռներ, fatigue-critical parts | Լիսեռներ, բերում է, Եռակցված կառույցներ | Pump/valve components where ASTM spec required |
| Հարաբերական արժեքը (նյութական + վերամշակում) | Medium — economical for complex castings | Medium–High — higher control/processing cost | High — specialized heat treatment and QA raise cost | Medium–High — higher machining/assembly cost for complex shapes | Medium — comparable when ASTM required |
12. Custom-Made Ductile Iron Precision Castings from Langhe
Langhe specializes in custom-made ductile iron precision castings, including EN-GJS-400-15, supporting a wide range of industries.
Through controlled melting, նոդլուլյացիա, and advanced molding processes, Langhe can deliver castings with consistent mechanical properties, Ամուր ծավալային հանդուրժողականություն, and tailored surface finishes.
In addition to casting, Langhe provides secondary operations such as machining, He երմամշակում, ծածկույթ, եւ ստուգում, enabling customers to receive ready-to-install components that meet specific technical and quality requirements.
13. Եզրափակում
EN-GJS-400-15 ductile iron is a versatile and reliable engineering material that bridges the gap between traditional cast iron and steel.
Դրա հավասարակշռված մեխանիկական հատկությունները, Գերազանց կուտելիություն, and cost efficiency make it a preferred choice for medium-duty structural, հիդրավլիկ, and mechanical components.
Պատշաճ դիզայն, Գործընթացի վերահսկում, and quality assurance are essential to fully realize its performance potential.
For applications requiring higher strength or fatigue resistance, alternative ductile iron grades or steels should be considered, but for many industrial uses, EN-GJS-400-15 remains an optimal and proven solution.
ՀՏՀ
Is EN-GJS-400-15 suitable for pressure-containing components?
Այո, it is commonly used for valves, պոմպեր, and pipe fittings when designed and tested according to relevant pressure standards.
Can EN-GJS-400-15 replace steel in structural applications?
In many cast components, yes—especially where complex geometry and vibration damping are required. Այնուամենայնիվ, weldability and very high fatigue demands may favor steel.
What matrix structure is typical for EN-GJS-400-15?
Primarily ferritic or ferritic–pearlitic, optimized to achieve high elongation and toughness.
How does section thickness affect properties?
Thicker sections cool more slowly and tend to form more ferrite, while thinner sections may develop more pearlite. Foundry process control compensates for these effects.
Can the properties be customized?
Այո. Through composition adjustment, պատվաստում, եւ ջերմային բուժում, foundries can fine-tune hardness, ուժ, and ductility within the EN-GJS-400-15 framework.
