ISO 683-15:1992

Overview

ISO 683-15:1992 specifies delivery requirements for valve steels for internal combustion engines. It covers wrought high‑alloy materials used for intake and exhaust valves, applicable to bars, wire, wire rod and forgings. The part defines material grades, chemical composition limits, delivery heat‑treatment conditions and surface finishes, and references general technical delivery rules in ISO 404. Annex A provides a technical supplement with property values after processing.

Key topics and requirements

• Scope and product forms: Applies to valve materials intended for reciprocating internal‑combustion engine valves in the forms of bars, wire, wire rod and forgings. Excludes wear/corrosion‑resistant alloys for valve seats.
• Grade classification: Materials are divided by structure into martensitic steels (typically for intake valves and valve stems) and austenitic alloys (primarily for exhaust valves). Specific grades and their chemical limits are listed in the standard (table references).
• Chemical composition and product analysis: Cast‑analysis limits are specified (table 1) with permissible deviations for product analysis (table 2). Product analysis sampling and preparation follow ISO 377 series and ISO/TR 9769 guidance.
• Heat‑treatment and surface finish: Delivery conditions (soft annealed, quenched & tempered, precipitation‑hardened, controlled cooled, etc.) and surface finishes (peeled, ground, polished, as‑rolled) must be agreed at order.
• Mechanical properties and testing: Mechanical property requirements at room temperature are given for specified conditions (see table 3 and Annex A). Testing methods reference ISO standards for tensile (ISO 6892), hardness (ISO 6506/6508), grain size (ISO 643), and wire/rod dimensions (ISO 8457‑1).
• Inspection and certification: Permitted documents include a test report, inspection certificate, or inspection report (ISO 10474). Sampling rules, number of tests per cast/heat, and retest/complaint procedures align with ISO 404.
• Marking and traceability: Coils/bundles and larger bars require labeling with manufacturer, grade, cast number and nominal size; guide bars are marked for bundles.

Applications and users

• Who uses ISO 683-15: Material engineers, valve manufacturers, automotive and engine OEMs, forging and heat‑treatment shops, quality/inspection teams, and procurement specialists specifying valve steels.
• Practical use cases: Specifying valve material for engine design, ordering valve stock (bars/wire/forgings), setting inspection/testing requirements for incoming materials, ensuring traceability and compliance with international delivery requirements.

Related standards

• ISO 404 - General technical delivery requirements for steel
• ISO 6892, ISO 6506, ISO 6508, ISO 643 - Test methods referenced for mechanical testing, hardness and grain size
• ISO 377‑1/2, ISO/TR 9769, ISO 10474 - Sampling, analysis and certification guidance

Keywords: ISO 683-15, valve steels, internal combustion engines, martensitic valve materials, austenitic valve alloys, chemical composition, heat‑treatment, mechanical testing, material delivery requirements.