How to resolve the issue where finished thin plates cannot be tested for chemical composition via Optical Emission Spectroscopy (OES)

How to resolve the issue where finished thin plates cannot be tested for chemical composition via Optical Emission Spectroscopy (OES) 

1.Sheet Grade & Dimensions: Inconel 625 Grade 2, 0.5*1236*2438

2.Problem:Quality inspection of nickel alloys often involves a common challenge with thin-gauge plates. When placed on an OES instrument for spark excitation testing, the high instantaneous electric current will heat the specimen until it glows red, burn through or even destroy it, making valid chemical composition analysis unachievable.

Conventional OES generates high excitation energy. Thick workpieces can conduct and dissipate heat quickly, whereas ultra-thin plates possess extremely low heat capacity. Unable to release heat promptly, thin specimens tend to develop oversized melting craters and suffer complete surface burnout. This not only yields inaccurate elemental readings and wastes samples, but also delays incoming material inspection, PMI verification and project delivery schedules.

3.Solution:During this third-party inspection service for the client, we addressed the above issue by digesting the specimen and conducting chemical composition testing with ICP analysis. The test results were successfully approved in the third-party inspection audit and client review.