Effect of Microstructure on Strain Aging and Hydrogen Embrittlement Behavior of Bake Hardening Steels

The strain aging and hydrogen embrittlement behavior of two bake hardening (BH) steels with different microstructures were investigated in this study. single-phase BH steel was composed fully ferrite, while the dual-phase consisted ferrite 3 % martensite. index (AI) measured to compare effect microstructure on behavior. As a small amount martensite is present steel, value higher than that AI showed relatively low value. After pre-strained up 20% electrochemically pre-charged hydrogen, other hand, slow rate test (SSRT) carried out examine pre-strain silver decoration technique thermal desorption analysis (TDA) performed understand mechanism from standpoint trapping. Regardless had lower resistance because formed acts as reversible trap site. decreased increasing which increases dislocation density. Based these results, it can be said introduction have negative impact resistance.