Figure 2-2 Non-metallic inclusion measurement system
Steel grade measurements take time to perform , depending on the number of inclusions found , on the order of minutes ; this is because the measurements are in the sub-micrometer range and each inclusion must be measured . With this time scale in mind , decreasing the measurement time by even one minute is a substantial amount . Even with the most modern algorithms and hardware , semi-automated measurements using ASTM or JIS point calculation methods can take between 2-6 minutes to perform 5 . The measurement times can be lowered with better measurement algorithms and autofocusing functions .
While the measurement system can help identify non-metallic inclusions , it is the inspector who must make the final evaluation of the samples and grade them according to regional regulations , international standards , and customer proprietary measurement methods 6 7 . This assessment requires considerable skill and training , so the steel manufacturer highly values their skilled inspectors .
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74 November 2021