ISO 15461:2018

Overview

ISO 15461:2018 - Steel forgings - Testing frequency, sampling conditions and test methods for mechanical tests provides harmonized guidance for specifying mechanical testing of open-die and closed-die steel forgings. The standard helps simplify product standards and purchase orders by offering a clear system of options for testing frequency, sampling conditions, and a compact designation system for test-unit options. It also specifies accepted test methods for room-temperature and elevated-temperature tensile testing, impact testing, and uniformity checks by hardness testing.

Key topics and technical requirements

• Scope and purpose: Guidelines for simplifying and harmonizing mechanical testing requirements in international standards and technical delivery conditions for steel forgings.
• Designation system: Symbols (e.g., CHD10) identify the composition of a test unit (same cast, forming cycle, shape/dimensions, heat treatment) and the sampling rules associated with that unit. The standard explains how to interpret these symbols in product standards and orders.
• Testing frequency and sampling:
  • The product standard or order must reference appropriate symbol(s) to specify test-unit composition, whether uniformity (hardness) checks are required, and the number of sample products per test unit.
  • Default sampling: generally one sample per sample product; some large or heavy forgings may require two samples per sample product (conditions are given in the standard).
  • Tensile and impact test pieces: one tensile test piece per sample; three impact test pieces per sample.
  • Preferred mass values for the symbol parameter n: 5, 10, 20, 40 tonnes (used to determine how many samples are required for a given test unit).
• Uniformity checks (hardness tests):
  • Symbols ending with “U” (Ux) indicate a percentage (x = 5 to 100) of products to be subjected to hardness testing for uniformity.
  • The standard sets rules for how many pieces to test, where to measure (surface location representative of the ruling section), and removal of decarburized zones/scale before testing.
• Test methods specified:
  • Room-temperature tensile tests (referencing ISO 6892-1)
  • Elevated-temperature tensile tests (referencing ISO 6892-2)
  • Charpy impact tests (referencing ISO 148-1)
  • Hardness tests for uniformity checks
• Normative references: ISO 377, ISO 404, ISO 3785, ISO 6892-1, ISO 6892-2, ISO 148-1.

Practical applications and users

ISO 15461:2018 is intended for:

• Standards committees and authors writing product standards for steel forgings
• Manufacturers and mills producing open-die and closed-die steel forgings
• Quality assurance / QC engineers and metallurgical labs performing mechanical tests
• Purchasing and inspection personnel specifying acceptance criteria in orders and technical delivery conditions

Using ISO 15461 helps reduce ambiguity in inspection plans, align sampling and test frequencies with production practice, and simplify conformity assessment across suppliers and buyers.

Related standards

• ISO 6892-1 / ISO 6892-2 (tensile testing)
• ISO 148-1 (Charpy impact)
• ISO 377 (sample preparation)
• ISO 404 (general delivery requirements)
• ISO 3785 (designation of test axes)

Keywords: ISO 15461:2018, steel forgings, testing frequency, sampling conditions, test methods, tensile tests, impact tests, hardness tests, uniformity checks, forgings QA.