How SakySteel Guarantees Consistent Quality in AH36 DH36 and EH36 Production

In the demanding world of shipbuilding and offshore engineering, high strength structural steel plates such as AH36, DH36, and EH36 play a crucial role in ensuring vessel integrity and long term reliability. These steel grades are widely used in hull structures, deck components, offshore platform legs, subsea modules, and heavy load bearing applications. Their performance directly influences the safety and durability of maritime projects. As a global supplier, sakysteel has established a comprehensive and highly controlled manufacturing system that ensures consistent quality from raw material selection to final inspection. This article explains how the company maintains strict standards throughout each production stage.

Importance of Consistent Quality in Marine Grade Steel

Shipbuilding steel must meet strict requirements for:

• High yield strength

• Excellent impact toughness

• Reliable weldability

• Stable chemical composition

• Defect free internal structure

Any deviation from these properties can compromise the safety of a vessel or offshore structure. Therefore, consistency is not optional but a core requirement for AH36 DH36 EH36 production.

Strict Raw Material Control

Quality assurance begins with the careful selection of raw materials. SakySteel works closely with certified steelmaking partners and conducts thorough inspections on each batch of input materials.

Raw Material Checks Include

• Chemical composition verification

• Inclusion control

• Furnace batch traceability

• Cleanliness level evaluation

Only materials that meet classification society standards such as ABS, DNV, LR, and CCS are accepted for further processing.

Advanced Steelmaking and Refining Technology

To ensure stable chemistry and mechanical performance, sakysteel relies on controlled steelmaking technologies such as:

• Basic Oxygen Furnace BOF

• Electric Arc Furnace EAF

• Ladle Furnace LF refining

• Vacuum Degassing VD

These processes help remove impurities, adjust alloy content, and ensure low sulfur and phosphorus levels. Clean refining leads to a uniform microstructure essential for high strength marine plates.

Benefits of Advanced Refining

• Improved toughness

• Higher cleanliness

• Reduced gas content

• Stable chemical accuracy

Chemical stability is the foundation of consistent AH36 DH36 EH36 steel properties.

Continuous Casting with Process Monitoring

After steelmaking, molten steel is cast into slabs. SakySteel’s casting process includes:

• Automatic mold level control

• Oscillation and cooling regulation

• Surface crack and segregation monitoring

This ensures slabs with excellent internal quality and minimal defects. Slabs are later conditioned to remove minor imperfections before entering rolling lines.

Precision Hot Rolling for Dimensional Accuracy

High strength shipbuilding plates depend heavily on the rolling process. SakySteel utilizes controlled rolling technology to achieve desired thickness, width, and microstructure.

Rolling Features Include

• Multi stand automated rolling lines

• Real time thickness and width monitoring

• Temperature tracking at each rolling stage

• Deformation control for uniform grain refinement

Hot rolling not only shapes the plates but also determines their mechanical performance. Uniform rolling enhances structural reliability throughout the entire plate.

Controlled Cooling for Microstructure Optimization

Cooling plays a critical role in defining final steel properties. SakySteel applies both laminar flow cooling and accelerated cooling depending on the grade and specification.

Cooling Control Provides

• Fine grained microstructure

• Improved toughness

• Higher yield strength

• Reduced residual stress

Accurate cooling ensures that AH36 DH36 EH36 plates meet their respective impact requirements at 0℃, 20℃, and 40℃.

Heat Treatment Options for Performance Enhancement

Depending on customer needs and classification society rules, sakysteel offers different heat treatment options:

Normalizing

Improves structural uniformity and toughness.

TMCP Thermo Mechanical Control Process

Enhances strength while improving weldability.

Quenching and Tempering QT

Maximizes strength and impact resistance, especially for EH36 used in harsh marine environments.

Heat treatment is closely monitored to ensure precise temperature control and consistent furnace performance.

Ultrasonic Testing UT for Internal Soundness

Internal defects can significantly reduce fatigue resistance and structural performance. SakySteel performs ultrasonic testing for every batch of AH36 DH36 EH36 plates.

UT Detects

• Laminations

• Inclusions

• Internal cracks

• Rolling defects

Testing follows standards such as EN 10160, ASTM A578, and class society requirements. Automated UT lines ensure full plate coverage and reliable results.

Surface and Dimensional Inspection

Before delivery, each plate undergoes rigorous surface and dimension checks.

Surface Tests Include

• Visual inspection for cracks, pits, or scale

• Surface conditioning if required

• Edge and corner evaluation

Dimensional Checks Include

• Thickness tolerance

• Width and length verification

• Flatness measurement according to EN 10029

• Straightness inspection

These checks ensure the plates meet manufacturing specifications for shipbuilding applications.

Mechanical Testing and Impact Verification

Mechanical performance is validated through laboratory testing, including:

• Tensile tests

• Yield strength verification

• Elongation measurements

• Impact testing at required temperatures

• Hardness evaluation

Each lot must pass all tests before release. Results are recorded in the Material Test Certificate MTC for customer traceability.

Strict Compliance with Classification Society Standards

SakySteel production is aligned with major class societies:

• ABS American Bureau of Shipping

• DNV

• Lloyds Register

• Bureau Veritas

• CCS China Classification Society

Compliance ensures that plates are suitable for global shipyards and offshore engineering projects.

Full Traceability and Documentation

Traceability is essential for high quality marine steel. SakySteel provides:

• Heat number tracking

• Rolling and heat treatment records

• NDT reports

• Mechanical property documentation

• MTC EN10204 3.1 certification

Complete documentation ensures transparency and reliability.

Packaging and Logistics Quality Assurance

Even after production, SakySteel ensures quality during transportation.

Measures Include

• Protective packaging to prevent corrosion

• Edge protection for safe handling

• Anti rust coating

• Secure loading for sea and land transport

This minimizes damage during international shipments.

Customer Feedback and Continuous Improvement

SakySteel values long term relationships with shipyards and engineering companies. Customer feedback is continually analyzed to improve production processes, enhance product performance, and develop better inspection routines.

This cycle of improvement ensures long lasting consistency and customer satisfaction.

Conclusion

Consistency in AH36 DH36 EH36 production requires strict control over every stage of manufacturing, from raw material selection to final inspection. Through advanced steelmaking processes, precision rolling, controlled cooling, rigorous testing, and complete documentation, sakysteel guarantees that each plate meets the highest standards of quality and reliability. As global demand for high performance shipbuilding steel continues to rise, SakySteel remains committed to delivering dependable materials that support safer and more efficient marine engineering projects.