Hydrogen-Induced Cracking (HIC) & SSCC
Engineering definition, metallurgical mechanisms, standard testing specifications, and manufacturing guidelines for closed-die forgings up to 50 kg.
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Stepwise internal cracking that occurs in steel exposed to wet sour gas (H2S) when atomic hydrogen diffuses into the metal and recombines into high-pressure molecular gas at inclusions.
Technical Explanation & Metallurgical Principles
In wet H2S environments, corrosion reactions release atomic hydrogen on the metal surface. These atoms diffuse into the steel matrix, accumulating at planar manganese sulfide (MnS) inclusions or laminations, recombining into hydrogen gas (H2) that creates massive internal pressure and blistering.
Key Engineering Specifications & Parameters
| Technical Parameter / Metric | Engineering Benchmark / Value |
|---|---|
| Test Protocol | NACE TM0284 / ASTM G38 96-hour exposure test |
| Sulfur Control | Ultra-low sulfur (S ≤ 0.005%) + calcium treatment |
Application at Jayesh Forge (Rajkot Plant)
All sour service forgings at Jayesh Forge utilize clean-melt, calcium-treated billets with verified HIC and sulfide stress cracking (SSCC) immunity.
Related Materials, Standards & Products
Applicable Material Grades
Related Metallurgical & Testing Terms
NACE MR0175 / ISO 15156 Sour Service Standard
The international standard defining material requirements for metallic equipment used in oil and gas production environments containing corrosive hydrogen sulfide (H2S).
Sour Service (Wet H2S Environment)
Piping and pressure equipment operating in environments containing moisture and hydrogen sulfide (H2S) at partial pressures exceeding NACE threshold limits.
Heat-Affected Zone (HAZ)
The portion of the base forging metal adjacent to a weld seam that has not melted but whose microstructure and properties have been modified by the intense heat of welding.
Questions Regarding Hydrogen-Induced Cracking (HIC) & SSCC
Calcium modifies elongated manganese sulfide stringers into spherical, benign calcium aluminates/sulfides that resist hydrogen trapping and delamination.
Request a Forging Quote with Hydrogen-Induced Cracking (HIC) & SSCC Compliance
Our Rajkot metallurgy desk is ready to review your technical drawings, testing protocols, and delivery schedules for custom closed-die forgings strictly up to 50 kg.