“…For organizing a process of linguistic classification of the intensity levels, subranges of the variable were heuristically defined, based on the calculation and analysis of the data of Changes SR , as follows: From the previous classification, all the steel casts with different levels of valve erosion intensity were analyzed, selecting 24 steel casts (steel grades: FE500, SAE1039, SAE1018, SAE 1026, SAE 1022, SAE 1021 and FeE500S). From these only two had high valve erosion (7 and 24: FE500), seven were defined as being medium erosion (3,6,10,13,18,20,22) and 15 as low erosion (1,2,4,5,8,9,11,12,14,15,16,17,19,21,23). This proportion is representative of the incidence rate of each level of intensity of the event in the population selected for the case study.…”