| Material Classification | ISO 1083 / EN 1563 | Graphite iron with spheroidal graphite is commonly specified as ductile cast iron. The material designation should identify the required mechanical property class and, where applicable, the impact or matrix requirement. | Metallographic examination combined with mechanical testing and chemical analysis. | Material specification, heat number, charge records, and traceable inspection report. |
| ASTM Mechanical Grade | ASTM A536 | Common reference grades include 60-40-18: minimum tensile strength 60 ksi (approximately 414 MPa), yield strength 40 ksi (approximately 276 MPa), and elongation 18%. | Tensile test using a calibrated universal testing machine. | Heat-specific tensile test report stating specimen location, dimensions, test temperature, and results. |
| Higher-Strength ASTM Grade | ASTM A536 | Common reference grades include 65-45-12: minimum tensile strength 65 ksi (approximately 448 MPa), yield strength 45 ksi (approximately 310 MPa), and elongation 12%. | Tensile testing in accordance with the applicable ASTM requirements. | Test certificate linked to the casting heat and the production lot. |
| Strength and Ductility | EN 1563 / ISO 1083 | Typical EN-GJS grades include EN-GJS-400-15 and EN-GJS-500-7. The first number represents the nominal minimum tensile strength in MPa, while the second represents the nominal minimum elongation percentage. Actual requirements depend on grade and section thickness. | Room-temperature tensile test on separately cast or cast-on specimens, as specified by the order and standard. | Mechanical property report showing grade, section category, specimen type, and acceptance criteria. |
| Yield Strength | ISO 6892-1 / ASTM E8/E8M | Yield strength or proof strength must meet the value specified for the selected material grade. The applicable definition should be stated, such as yield point or 0.2% proof strength. | Extensometer-based tensile testing with controlled loading rate. | Machine calibration certificate, stress-strain data, and test result summary. |
| Hardness | ISO 6506-1 / ASTM E10 | Hardness limits are normally agreed according to the grade, matrix structure, and application. Brinell hardness is widely used for ductile iron castings. | Brinell hardness testing, normally using a carbide ball and specified test force. | Hardness map showing measurement locations, values, surface preparation, and equipment identification. |
| Impact Toughness | ISO 148-1 / EN 1563 | Impact energy requirements apply when a grade or purchase specification includes impact toughness. The test temperature and minimum absorbed energy must be defined in advance. | Charpy V-notch impact test at the specified temperature. | Impact test report including notch orientation, test temperature, individual values, and average value. |
| Graphite Shape and Distribution | ISO 945-1 | For spheroidal graphite iron, graphite should predominantly appear as compact or nodular particles. Nodularity, particle count, size distribution, and graphite degeneration should be controlled according to the agreed specification. | Metallographic preparation, optical microscopy, image analysis, and comparison with reference classifications. | Microstructure photographs, nodularity percentage, particle count, and evaluation magnification. |
| Matrix Structure | ISO 1083 / EN 1563 | The ferrite-pearlite balance, carbide content, and other matrix features should be compatible with the required strength, ductility, wear resistance, and machinability. | Etched and unetched metallographic examination, usually with optical microscopy. | Metallographic report identifying matrix constituents and any carbides, inclusions, or abnormal structures. |
| Chemical Composition | Purchasing Specification / Grade Standard | Carbon, silicon, manganese, sulfur, phosphorus, magnesium, and alloying elements should remain within the approved range for the selected grade and casting process. Limits are grade- and application-dependent rather than universal. | Optical emission spectroscopy or X-ray fluorescence, with thermal analysis where process control requires it. | Heat chemistry certificate, spectrometer calibration status, and furnace charge traceability. |
| Dimensional Accuracy | ISO 8062-3 | Dimensional tolerances should be agreed by the required casting tolerance grade, drawing requirements, machining allowance, datum structure, and inspection method. | Coordinate measuring machine, calibrated gauges, vernier instruments, or dedicated fixtures. | Dimensional inspection report with drawing revision, measured dimensions, tolerances, and equipment details. |
| Surface Quality | Drawing and Purchase Specification | Castings should be free from unacceptable cracks, cold shuts, misruns, harmful shrinkage, excessive sand adherence, and other discontinuities defined as rejectable by the drawing or quality plan. | Visual inspection, surface profile checks, and dimensional verification after cleaning or shot blasting. | Visual acceptance criteria, inspection checklist, photographs where required, and nonconformance records. |
| Internal Soundness | ASTM E446 / ASTM E280 or Customer Specification | Internal shrinkage, porosity, inclusions, and other discontinuities must remain within the acceptance level specified for the component's function and critical areas. | Radiographic testing, ultrasonic testing, or other approved volumetric examination. | NDT procedure, operator qualification, inspection coverage, image or scan records, and acceptance evaluation. |
| Surface Crack Detection | ASTM E1417/E1417M / ISO 3452-1 | Liquid penetrant testing is suitable for detecting open-to-surface discontinuities on appropriately prepared, non-porous surfaces. | Visible or fluorescent penetrant inspection after cleaning, dwell, removal, and developer application. | NDT report identifying inspected areas, penetrant system, acceptance criteria, and qualified personnel. |
| Magnetic Particle Inspection | ASTM E1444/E1444M / ISO 9934-1 | Magnetic particle testing can detect surface and near-surface discontinuities in ferromagnetic ductile iron castings. | Dry or wet magnetic particle examination using a calibrated yoke or suitable magnetizing equipment. | Procedure qualification, equipment verification, inspection map, indications record, and acceptance decision. |
| Pressure or Leak Integrity | Customer Drawing / Application Standard | Pressure-retaining castings should meet the specified hydrostatic, pneumatic, or functional leak-tightness requirement. Pressure, holding time, medium, and allowable leakage must be documented. | Hydrostatic pressure test, air-under-water test, pressure-decay test, or helium leak test where specified. | Pressure-test record showing test pressure, duration, equipment identification, and result. |
| Heat Treatment | Approved Process Specification | Heat treatment may be required to obtain a specified ferritic, pearlitic, austempered, or stress-relieved structure. The cycle must be validated for the casting geometry. | Recorded furnace temperature, time-at-temperature, cooling rate, and post-treatment mechanical or microstructural verification. | Furnace chart, batch identification, thermocouple calibration, and heat-treatment certificate. |
| Quality Management Certification | ISO 9001 | ISO 9001 certification demonstrates that the organization operates a documented quality management system. It does not by itself certify a particular casting grade or guarantee product conformity. | Assessment and surveillance audit by an accredited certification body. | Valid certificate, scope of certification, issuing body, certificate number, and expiry date. |
| Environmental Management | ISO 14001 | ISO 14001 addresses environmental management processes, legal compliance controls, and continual improvement. It is generally a supplier-management qualification rather than a material-performance certificate. | Certification audit and periodic surveillance audit. | Valid certificate and clearly stated site and activity scope. |
| Occupational Health and Safety | ISO 45001 | ISO 45001 covers occupational health and safety management systems, including hazard identification and operational controls. | Third-party management-system audit. | Valid certificate showing the certified manufacturing location and scope. |
| Material Traceability | EN 10204 | Inspection documents may be supplied as an inspection certificate or inspection report. A 3.1 certificate generally provides manufacturer-declared, batch-specific results; a 3.2 certificate involves additional validation by an authorized representative or purchaser's representative. | Review of heat numbers, production records, test results, and document signatures. | Traceable EN 10204 inspection document linked to the casting lot and purchase order. |
| Regulatory Compliance | Application-Dependent Requirements | Pressure equipment, machinery, automotive, rail, food-contact, drinking-water, and construction applications can impose different regulatory or customer requirements. Certification should be selected according to the final use and destination market. | Conformity assessment, product testing, technical-file review, or third-party approval as required by the applicable regulation. | Declaration of conformity, applicable approvals, test reports, risk assessment, and technical documentation where required. |
| Supplier Prequalification | Customer Quality Agreement | A qualified supplier should demonstrate stable melting, inoculation, spheroidization, molding, heat-treatment, machining, inspection, and corrective-action processes. | Process audit, sample approval, capability review, first-article inspection, and periodic performance monitoring. | Process flow chart, control plan, PFMEA, inspection plan, capability data, corrective-action procedure, and audit records. |
