Reduction of weld metal diffusible hydrogen content by adding colloidal nanosilica to the electrode coating

• Anti-hygroscopic coated electrodes were fabricated for the first time by adding colloidal nanosilica to the flux binder.
• Colloidal nanosilica was uniformly dispersed in the electrode coating.
• Colloidal nanosilica reduced the hygroscopicity of the electrode coating.
• The weld metal diffusible hydrogen content was greatly decreased.

In the present study, a novel method for reducing diffusible hydrogen in the weld metals was developed by adding colloidal nanosilica to the electrode coating. Shielded metal arc weld deposits were prepared by varying colloidal nanosilica content in the range of 0–30 wt.%. The diffusible hydrogen and metallographic tests were carried out on the weld metals to evaluate the effect of colloidal nanosilica addition on the weld metal properties. The test results showed that the weld metal diffusible hydrogen content was greatly decreased when using the coated electrodes containing colloidal nanosilica.

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