ISO 17577:2016

Overview

ISO 17577:2016 defines a standardized method for ultrasonic testing (UT) of uncoated steel flat products with nominal thicknesses from 6 mm to 200 mm. Using the pulse-echo technique, the standard covers both manual and automated inspection for internal discontinuities (planar/laminar imperfections, inclusion bands, clusters). It sets out test principles, equipment and probe requirements, calibration and sensitivity rules, scanning plans, acceptance criteria and reporting - ensuring consistent, reproducible non‑destructive testing (NDT) of steel plate and strip.

Key topics and technical requirements

• Scope & applicability: Non‑alloyed and alloyed steels; can be applied to austenitic and duplex steels only if signal‑to‑noise allows. For welded tube plate used in welded steel tubes, ISO 10893‑9 applies unless agreed otherwise.
• Testing principle: Pulse‑echo inspection with normal incidence; defect sizing by the DGS (distance‑gain‑size) method and area contouring by the 6 dB drop technique. Examination normally from one side only.
• Personnel qualifications: Operators must be qualified (minimum Level 1 for manual work; Level 2/3 responsible for automated testing) per ISO 9712 / ISO 11484 or equivalent.
• Equipment & performance:
  • Instruments with gain calibrated in decibels, time‑base control, A‑scan display for manual testing, gating and output for recording/mapping.
  • Linearity limits for amplifiers (vertical/horizontal) and recommended annual checks.
  • Dead zone limits: single‑element probe dead zone ≤ 15% of thickness or 15 mm (whichever smaller); ≤ 1.5 mm for products < 10 mm.
• Probes: Guidance (from table) recommends dual‑element probes for 6–60 mm and single or dual for 60–200 mm; nominal frequency typically 2–5 MHz; transducer dimension ≤ 30 mm.
• Automated systems: Requirements for mechanical scanning, probe holders following contour, data acquisition, DAC/DGS capability, PRF control tied to scan speed, and mapping/location output.
• Calibration & evaluation: Use reference blocks, DAC/DGS, alarm gates, and documented sensitivity/range settings. In disputes, the standard’s prescribed methods prevail.

Practical applications & who uses it

• Manufacturers and suppliers of steel plate, strip and flat products for quality control and acceptance testing.
• NDT service providers performing production inspection, incoming material testing, or supplier verification.
• Fabricators and purchasers specifying acceptance criteria for internal defects in structural, pressure‑containing or formed steel components.

Related standards

• ISO 9712 - Qualification and certification of NDT personnel
• ISO 10893‑9 - Automated UT for strip/plate used in welded steel tubes
• ISO 11484 - Employer’s qualification system for NDT personnel

ISO 17577 supports reliable ultrasonic inspection practices, helping organizations achieve consistent detection, sizing and documentation of internal discontinuities in steel flat products.