Determination and characterization of non-metallic inclusions in low alloy steel

Representativeness and accuracy of inclusion analysis should be figured out for the determination and characterization of non-metallic inclusions in low alloy steel.The non-metallic inclusions components in low alloy steel,as well as the single spark pulse distribution and spectra was studied. In combination with quantitative metallography,SEM and EDS,the main existence state of the inclusions in low alloy steel and the relevance between abnormal spectral signals and the particle number and size of the inclusions were explored.It was found that the particle number of larger inclusions had agreater significant impact on the relative frequency of the abnormal sparks,and the ratio of abnormal average intensity to the overall average intensity was also closely related with the average particle size of the inclusion.When the contents of the main elements in low alloy steel were measured,the system could identify and detect non-metallic inclusions with single spark pulse distribution and spectra at the same time and thus realized the qualitative and quantitative determination of non-metallic inclusions with the combination of physical means,namely,metallography and SEM,so it is suitable for the daily quality control of low alloy steels.