Research on the preparation method of steel sample for hydrogen analysis

The preparation method of steel sample had negligible influence on the determination results of hydrogen. Especially for ultralow hydrogen less than a millionth, the sample preparation was the key and necessary step. The steel samples for hydrogen determination prepared by various methods were studied with special hydrogen analyzer. The results showed that the surface effect could be effectively eliminated by ultrasonic cleaning. This method was applicable for the post treatment of samples prepared by lathe turning and manually filing. The determination results of hydrogen content in samples prepared by different methods were consistent. Six steel samples and six standard steel samples for hydrogen were treated by ultrasonic cleaning, and no significant hydrogen loss was observed. The results indicated that the ultrasonic cleaning could remove the surface pollution of ultralow hydrogen (0.X μg/g) steel samples. The excellent effect of 5-10 times could be obtained. The determination results were satisfactory and the reliability was high. The experimental fact showed that the ultrasonic cleaning was effective to clean the surface pollution of sample. Meanwhile, the hydrogen loss caused was ignorable. The proposed method could be extended to the preparation of sample for hydrogen analysis.