Boron alloying and laser treatment to improve corrosion and hydrogen resistance of 25G steel

摘要

Alloying of the low-carbon 25G steel with 0.003 percent of boron decreased its susceptibility to the general and pitting corrosion and to anodic dissolution in Cl~- and SO_4~= containing solution. Laser quenching of the boron alloyed steel caused the passivity of steel and the further decrease in susceptibility to corrosion. Boron alloying hampered the hydrogen transport, increased the hydrogen trapping, and the resistance to hydrogen induced degradation. The further improvement of resistance to hydrogen degradation has been achieved by the laser quenching, despite the increase in the metal" strength. The beneficial effect of the laser treatment might be a result of formation of specific microstructure, or due to high compressive stresses within the laser treated surface layer. The increase in corrosion and hydrogen resistance due to the boron alloying and laser treatment also contributes to the increase in the wear resistance under mechanical action and in the aggressive soil environment.