Uncertainty Evaluation on Measurement Results of Length of Non-metallic Inclusions

According to the standard of JJF 1059-1999 and GB/T 10561-2005, the length of non-metallic inclusions in LZ50 steel shaft blank whose rolling proportion is more than 3 was observed by optical microscope and measured by metallographical analysis software in the multiple of 100 by method A of GB/T 10561-2005. The source of uncertainty in measuring the length of non-metallic inclusions was analyzed, every uncertainty component was evaluated, and finally the expanded uncertainty and measuring uncertainty report was offered. The results show that the main inclusions in LZ50 steel were type C silicate inclusions. The measuring uncertainty report was the measurement result of length of type C non-metallic inclusions was (632±6) μm, k=2.