ISO 683-2:2016

Overview

ISO 683-2:2016 - "Heat-treatable steels, alloy steels and free-cutting steels - Part 2: Alloy steels for quenching and tempering" - defines the technical delivery requirements for a range of product forms manufactured from alloy steels intended for quenching and tempering. The standard covers semi-finished products (blooms, billets, slabs), bars, wire rod, finished flat products, and hammer/drop forgings produced from the alloy steels listed in the document. It specifies heat‑treatment and surface conditions at delivery and the requirements needed when parts are to be quenched and tempered, austempered, or flame/induction hardened.

Key Topics

• Scope of products: semi‑finished products, bars, wire rod, finished flats and forgings (see Table references in the standard).
• Heat‑treatment conditions: permitted delivery conditions for different product types and guidance for quenching and tempering (including austempering where applicable).
• Chemical composition & mechanical properties: required compositional limits and mechanical requirements tied to ruling section sizes (mechanical property limits are size‑dependent and limited to sizes in Table 8).
• Hardenability and surface hardness: verification methods and limits (referenced tests such as Jominy end‑quench for hardenability).
• Surface and dimensional requirements: surface conditions (Table 2), decarburization limits, shape, dimensions and tolerances.
• Quality characteristics: grain size, non‑metallic inclusions, internal soundness, machinability and cold shearability.
• Inspection and testing: prescribed test methods and inspection documents (mechanical tests, hardness tests, Charpy impact, chemical analysis) and frequency of testing.
• Ordering and traceability: mandatory purchaser information, options/supplementary requirements can be agreed at enquiry/order, and cast traceability rules.
• Referenced test standards: e.g., ISO 6892‑1 (tensile), ISO 148‑1 (Charpy), ISO 642 (Jominy), ISO 6506/6508 (Brinell/Rockwell hardness).

Applications

ISO 683-2 is used by:

• Steel producers specifying and delivering alloy steels for quench-and-temper service.
• Heat‑treatment shops and metallurgical labs performing hardness, hardenability and mechanical tests.
• OEMs and component manufacturers producing gears, shafts, machine parts, and forged components requiring quenched and tempered or induction/flame‑hardened properties.
• Procurement, QA and inspection teams ensuring delivered material meets contractual technical delivery requirements. Practical benefits include consistent material performance, clear acceptance criteria for mechanical and surface properties, and reduced supply-chain disputes.

Related Standards

• ISO 404 - General technical delivery requirements for steel products (applicable in addition).
• ISO 683‑18 and ISO 4954 - for bright products and bars/wire rod for cold heading (ISO 683‑2 does not apply to these).
• Normative test standards referenced in ISO 683‑2 (ISO 6892‑1, ISO 148‑1, ISO 642, ISO 6506/6508, etc.) are used to verify compliance.

Keywords: ISO 683-2, alloy steels for quenching and tempering, heat-treatable steels, technical delivery requirements, hardenability, heat treatment conditions, mechanical properties.