Abstract
The material test report (MTR) provides proof of the mechanical properties of a steel product and confirms that the tests required have been performed and are satisfactory. For this purpose, test pieces that are representative of the steel product are destructively tested and the results are given on the MTR. The MTR is essential as one cannot determine the mechanical properties non-destructively. The standard way of linking the MTR and the product is done by a specific mark on the product, usually the batch/heat number which is given in the MTR. But what if there is no confidence the MTR relates to the steel product? The steel product will then have limited value because there is no proof of compliance with the requirements.
A chemical composition is usually mentioned on the MTR. This is the chemical composition of the ladle, also called the heat analysis. The chemical composition does not change during the process of manufacturing a steel product. Therefore it can be considered as the “DNA” of the steel.
This paper will explain the use of mobile optical emission spectrometry (OES) as a reliable method for measuring the chemical composition of a steel product. The measured chemical composition, the DNA of the steel, is compared with the heat analysis. If the material test report relates to the steel product, the differences between the two chemical compositions will be very small. If differences in the composition are large we can see that the MTR and steel product do not relate to each other. This does not mean that the steel product does not meet the specified mechanical properties. Only the relationship with the associated MTR is no longer there and thus proof that the steel product complies with requirements.
