On December 5, 2025, a group standard led by Nanjing Kerun Industrial Media Co., Ltd. (“Kerun”) and issued under the China Machinery Industry Federation successfully passed technical review.
Titled Determination of Zirconium Mass per Unit Area in Zirconium-Based Conversion Coatings on Metallic Materials — X-ray Fluorescence Spectrometry, the standard focuses on a critical performance indicator of zirconium-based conversion coatings—zirconium content per unit area. For the first time in the industry, it establishes a quantifiable, reproducible, and scalable unified testing methodology, providing essential technical support for the standardized application and large-scale deployment of zirconium-based conversion coating technologies.
Image | Announcement by the China Machinery Industry Federation
Image | Group Standard Review Meeting
As a key green alternative to phosphating and chromate treatments, zirconium-based conversion coatings have been widely adopted in pretreatment processes for automotive and high-end manufacturing applications. In practical engineering use, however, while zirconium content is generally recognized as a critical indicator for evaluating coating performance, the industry has long lacked a unified and reliable quantitative testing method. Variations in testing approaches among laboratories and limited comparability across different instruments have meant that assessments of zirconium content often rely heavily on empirical judgment, constraining standardized evaluation and stable, large-scale application of the technology.
To address these challenges, this standard is explicitly positioned as a testing-method group standard, focusing on practical questions of how to measure, how to measure accurately, and how to ensure applicability in engineering environments. The standard introduces a dual-instrument calibration methodology that integrates ICP-OES and X-ray fluorescence (XRF) techniques. High-accuracy reference values for zirconium content are first established using the ICP-OES method, after which XRF is employed to construct engineering-grade working curves. This approach enables rapid, non-destructive testing of subsequent samples, effectively translating laboratory-level measurement accuracy into a reproducible and deployable solution suitable for on-site engineering applications.
Image | Schematic Illustration of the Principle Behind the Standardized Testing Method
In terms of structure and technical detail, the standard strictly complies with applicable standardization requirements. It provides explicit specifications covering sample dimensions, surface area determination, testing conditions, operational procedures, as well as repeatability and reproducibility criteria. These provisions ensure strong executability and methodological consistency, effectively preventing significant deviations in test results caused by differences in personnel or equipment.
The development of this standard is grounded in a systematic synthesis of long-term engineering practice. By effectively integrating the strengths of multiple analytical techniques, it demonstrates a deep understanding of both the application scenarios and practical engineering requirements of zirconium-based conversion coatings. Kerun’s leadership in drafting this group standard not only reflects its sustained technical expertise in this field, but also marks a clear evolution from a technology application participant to an active contributor in the co-creation of industry rules and standards.
Image | Group Photo of Review Panel and Industry Experts at Kerun’s Intelligent Manufacturing Base
The successful review of this standard not only establishes a unified, quantitative, and comparable testing basis for a key performance indicator of zirconium-based conversion coatings, but also represents a pivotal step in advancing industry measurement methods from experience-based judgment toward engineering-level quantification. Looking ahead, Kerun will continue to leverage its technological leadership to promote the standardized and large-scale application of zirconium-based conversion coatings and related green, high-end manufacturing technologies, providing strong support for the industry’s sustainable development.
