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- 2010 (4)
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- Hydrogen (4) (entfernen)
This international round robin test served to scrutinize the procedures specified in ISO/DIS 3690:2009 for determining the diffusible hydrogen content in weld metals with bcc-lattice structure. It was specifically intended to check in what respect the specifications defined in the indicated standards for specimen preparation, storage and hydrogen analysis provide comparable measurement results. The round robin test is presented comprising comparative measurements at various degassing temperatures using hot extraction techniques and a thermal conductivity detector (TCD). A major focus of this investigation was the examination of the maximum degassing temperature for analysing the diffusible hydrogen in materials with bcc-lattice structure. The analyses were performed using two different stick electrodes and three different filler wires. As a significant result it was found that no deviations or increases, were detected in the measured contents of diffusible hydrogen for the investigated degassing temperatures ranging between 45 degrees C and 400 degrees C. Hydrogen analyses for contents below HD = 1.5 ml/100 g with the hot extraction techniques in conjunction with TCD applied in this study led to considerable relative standard deviations.
Comparative study between hot extraction methods and mercury method - a national round robin test
(2010)
Comparative study between hot extraction methods and mercury method - a national round robin test
(2010)
A round robin test is presented comprising comparative measurements using hot extraction at different degassing temperatures as well as the mercury method. A major focus of the investigation was verification of the maximum degassing temperature for analysing the diffusible hydrogen in weld metals with bcc-lattice structure. The analyses were executed using a basic stick electrode with high weld metal cracking, a high-alloyed supermartensitic filler wire with different hydrogen contents in the shielding gas and a high-strength solid wire. The results show that degassing temperatures of 150 degrees C and 400 degrees C do not lead to an increase in the measured contents of diffusible hydrogen as compared to measurements at room temperature. The measuring techniques and procedures specified in ISO/DIS 3690:2009 for determining the diffusible hydrogen content in weld metals with bcc-lattice structure yield approximately the same results. This is to say that the mercury method and the hot extraction methods with thermal conductivity detector (TCD) can be regarded as equivalent reference methods.