ISO 4996:2014

Overview - ISO 4996:2014 - Hot-rolled steel sheet (high yield stress structural quality)

ISO 4996:2014 specifies requirements for hot-rolled steel sheet of high yield stress structural quality produced with microalloying elements. The standard covers sheet produced on wide strip mills, normally supplied in the delivered condition for structural use where defined mechanical properties are required. Typical uses include bolting, riveting and welding in structural assemblies. The standard excludes steels for boilers/pressure vessels, commercial or drawing quality (ISO 3573), weathering steels, steels to be re-rolled to cold-reducing products, and steels with enhanced formability beyond the standard’s scope.

Key topics and technical requirements

• Grades and mechanical properties: Defined high-yield grades include HS355, HS390, HS420, HS460 and HS490 with specified minimum yield strengths (e.g. HS355 = 355 MPa, HS490 = 490 MPa) and corresponding tensile strength ranges (e.g. HS355 Rm ≈ 430 MPa, HS490 Rm ≈ 570 MPa). Minimum elongation requirements are given for defined gauge lengths.
• Chemical composition: Heat analysis limits are specified (for example C ≤ 0.20%, Mn ≤ 1.60–1.70% depending on grade, Si ≤ 0.50%, P and S ≤ 0.035%). Microalloying limits: Ti ≤ 0.10%, Nb ≤ 0.08%, V ≤ 0.10%; sum of Ti+Nb+V ≤ 0.22% and each ≥ 0.005% where present. Limits on Cu, Ni, Cr and Mo and their combined maximums are provided.
• Dimensions and form: Typical thickness range 1.6 mm to 6 mm; widths normally ≥ 600 mm; supplied in coils or cut lengths.
• Manufacture and testing: Steelmaking processes are at the manufacturer’s discretion unless otherwise agreed. Heat analysis is required for each heat; purchaser product analysis and sampling methods are agreed at order. Tensile testing follows ISO 6892-1 procedures.
• Weldability and surface condition: Material is suitable for welding with appropriate procedures; descaled (pickled) surfaces may require special handling. Note: spot welding becomes more difficult as carbon content exceeds ~0.15%.
• Tolerances, inspection and marking: Dimensional and shape tolerances, sampling, retest and acceptance rules are specified, along with coil size and marking requirements.

Applications and users

ISO 4996:2014 is used by:

• Structural steel manufacturers and mills
• Fabricators and welders specifying material for buildings, bridges, and heavy equipment
• Structural engineers and specifiers requiring high-strength sheet
• Procurement and quality inspectors verifying compliance with chemical, mechanical and dimensional requirements

Related standards

• ISO 3573 (drawing/commercial quality steels)
• ISO 6892-1 (tensile testing at ambient temperature)
• ISO 16160 (dimensional and shape tolerances for hot-rolled sheet)

Keywords: ISO 4996:2014, hot-rolled steel sheet, high yield stress, microalloying, structural quality, HS355, HS490, chemical composition, weldability, mechanical properties.