Reference blocks generated by laser treatment for grinding burn inspection

Zösch, Antje; imq - Ingenieurbetrieb für Materialprüfung, Qualitätssicherung und Schweißtechnik GmbH; Germany

Zösch, A.; imq Ingenieurbetrieb GmbH; Germany
Härtel, K.; imq Ingenieurbetrieb GmbH; Germany
Koch, F.; imq Ingenieurbetrieb GmbH; Germany
Seidel, M.; imq Ingenieurbetrieb GmbH; Germany

ID: ECNDT-0036-2018
Download: PDF
Session: Magnetic Methods - Barkhausen 2
Room: R2
Date: 2018-06-11
Time: 15:20 - 15:40

Grinding burn is defined as a result of unintentional heat impact during processing of hardened steel surfaces such as claimed surfaces of gear parts. Depending on heat intensity local tempered zones or re-hardened zones are generated. The occurrence of grinding burn within the production process is a risk for the safety of the components. Different test methods are applied to verify grinding burn. Surface temper etching (STE) is the most commonly used method for detecting grinding burn up to now. It is the only standardized testing method (ISO 14 104:2014). However, industrial automation of this method is limited and the evaluation of etched parts is performed visually by an operator. For this reason, non-destructive methods are of high interest as they allow reproducible detection of grinding burn without influence of human factors. The 3MA-methode, the Barkhausen noise analysis and in recent times, eddy current testing are already applied.
Components with defined defects of different characteristics are required for the evaluating of non-destructive test methods as well as for STE according to ISO 14104. Generation of reproducible grinding burn on components cause problems regarding to size and depth of the influenced area. An alternative is the generation of artificial defects. Artificial defects have to be fabricated reproducibly in size, location and intensity and they have to show similar physical behavior like real defects.
Experiences and results of manufacturing and assessment of reference blocks with artificial defects generated by laser treatment for grinding burn detection are presented. The artificial defects meet the requirements mentioned above and may be used for non-destructive testing methods as well as for STE. The reference blocks are used for calibration of the test equipment, especially the required test sensitivity. In addition, reference blocks are applied in certain intervals within the process in order to guarantee testing reliability.