Effect of Surface Processing Variables on Hydrogen Embrittlement of Steel Fasteners
Author | : Salim Brahimi |
Publisher | : |
Total Pages | : 248 |
Release | : 2007 |
ISBN-10 | : OCLC:316162699 |
ISBN-13 | : |
Rating | : 4/5 ( Downloads) |
Download or read book Effect of Surface Processing Variables on Hydrogen Embrittlement of Steel Fasteners written by Salim Brahimi and published by . This book was released on 2007 with total page 248 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Incremental step load testing was used in accordance with ASTM F1940 to rank a number coating processes used in the fastener industry for their propensity to cause internal hydrogen embrittlement. The results showed that coating permeability has a first order effect, while the quantity of hydrogen introduced by the process has a second order effect. Pure zinc electroplating processes, alkaline and acid, were found to be the most embrittling, owing to the low permeability of zinc. The least embrittling processes were zinc-nickel, alkaline and acid, owing to the high permeability of Zn-Ni coatings. Non-electrolytic processes, namely phosphating, mechanical galvanising, DacrometRTM and Magni 555RTM were found to be non-embrittling. Hot dip galvanising was found to be highly embrittling, evidently due to trapped hydrogen being released by the thermal shock of up-quenching upon immersion in molten zinc. The full effect of up-quenching on the metallurgical and mechanical properties of high strength steel requires further investigation." --