ASTM E749/E749M-17(2021) PDF

Overview

ASTM E749/E749M-17(2021): Standard Practice for Acoustic Emission Monitoring During Continuous Welding details procedures for the acoustic emission (AE) monitoring of weldments during and immediately after fabrication by continuous welding processes. The standard, developed by ASTM Committee E07 on Nondestructive Testing, provides guidance for detecting and locating AE sources in welds and their heat-affected zones, promoting improved weld quality and cost-effective in-process defect handling. Real-time monitoring allows for immediate feedback on weld integrity, supporting timely repair and efficient application of other nondestructive evaluation (NDE) methods.

Key Topics

• Scope and Significance

  • Recommendations for AE monitoring during fabrication by continuous welding.
  • Applicability to detection and location of AE sources in weldments and heat-affected zones.
  • Real-time assessment and immediate data display, enabling fast decision-making and focused repairs.
  • Suitability for materials including low-carbon steels, low-alloy steels, stainless steels, and some aluminum alloys.

• Planning and Preparation

  • System or object description: Clearly define what will be monitored or examined.
  • Extent of monitoring: Determine if this includes the entire weld or specific passes.
  • Sensor mounting: Address limitations or restrictions, ensuring sensors remain operational within specified temperature ranges and are not disturbed by welding equipment.
  • Verification parameters: Establish and maintain AE system criteria such as sensitivity and location accuracy.
  • Operator qualifications: Utilize personnel certified according to recognized NDT qualification practices (e.g., ISO 9712, SNT-TC-1A, ANSI/ASNT CP-189).

• Instrumentation

  • Proper selection and placement of AE sensors for optimal response from weldments.
  • Use of frequency bandpass filters to minimize noise from non-welding sources.
  • Adjustments to system gain and calibration verified through AE simulators.
  • Procedures for single-, two-, or three-channel monitoring, and considerations for stationary or moving sensors.

• Data Recording and Interpretation

  • Requirements for permanent records of AE activity, including equipment settings, sensor locations, and calibration results.
  • Interpretation of AE data against baseline signals from acceptable welds.
  • Need for follow-up NDT methods (visual, ultrasonic, radiography) based on AE monitoring results.
  • Documentation of actions taken (e.g., repairs performed either during or after welding).

Applications

This standard is valuable for professionals in welding fabrication, quality assurance, and maintenance in industries such as:

• Structural Steel Fabrication: Enabling early detection of flaws during the construction of large steel frameworks.
• Pipeline Construction: Monitoring weld integrity during pipeline assembly in oil, gas, and water transport infrastructure.
• Shipbuilding & Aerospace: Ensuring welding quality in critical safety-related applications where reliability is paramount.
• Manufacturing: Supporting an efficient production process with minimal downtime and cost by pinpointing defects when repairs are most convenient.

By applying ASTM E749/E749M-17(2021), organizations can streamline defect detection, minimize the cost of repairs, ensure regulatory compliance, and achieve higher levels of weld quality control.

Related Standards

Acoustic emission monitoring during continuous welding is closely linked to a range of NDE and personnel qualification standards, including:

• ASTM E543: Specification for Agencies Performing Nondestructive Testing
• ASTM E569: Practice for Acoustic Emission Monitoring of Structures During Controlled Stimulation
• ASTM E650: Guide for Mounting Piezoelectric Acoustic Emission Sensors
• ASTM E1316: Terminology for Nondestructive Examinations
• ASNT SNT-TC-1A and ANSI/ASNT CP-189: Recommended practices and standards for NDT personnel qualification and certification
• AIA NAS-410: Certification and Qualification of Nondestructive Testing Personnel
• ISO 9712: Qualification and Certification of NDT Personnel

These related standards provide a comprehensive framework for AE monitoring, personnel qualification, and equipment verification, helping organizations execute continuous welding projects that meet rigorous quality and safety requirements.