Hot dip galvanized steel sheet is widely used in the automotive field because of its advantages of low cost, thick hot dip galvanized layer, reducing body defects, improving vehicle performance, and beautifying surface appearance. However, the zinc slag defects on the surface of the steel plate significantly reduce the surface quality of the steel plate. In this paper, the morphology of zinc slag on the surface of a pure hot-dip galvanized steel sheet was analyzed by scanning electron microscope. The results showed that the zinc slag defects on the surface of pure hot-dip galvanized steel strip was round, and the size was large, about 700 um. By adjusting the air knife pressure, the aluminum content in the zinc tank, and the opening of the RCS fan, the number and size of zinc slag defects on the surface of pure hot-dip galvanized steel strip can be significantly reduced. As a result, the steel plate was improved.
The chitin‐based peritrophic matrix (PM) is a structure critical for both gut immunity and digestion in invertebrates. PM was traditionally considered lost in all vertebrates, but a PM‐like chitinous membrane (CM) has recently been discovered in fishes, which may increase the knowledge on vertebrate gut physiology and structural evolution. Here, we show that in zebrafish, the CM affects ingestion behavior, microbial homeostasis, epithelial renewal, digestion, growth, and longevity. Young mutant fish without CM appear healthy and are able to complete their life cycle normally, but with increasing age they develop gut inflammation, resulting in gut atrophy. Unlike mammals, zebrafish have no visible gel‐forming mucin layers to protect their gut epithelia, but at least in young fish, the CM is not a prerequisite for the antibacterial gut immunity. These findings provide new insights into the role of the CM in fish prosperity and its eventual loss in tetrapods. These findings may also help to improve fish health and conservation, as well as to advance the understanding of vertebrate gut physiology and human intestinal diseases.
The bake hardening steel can better solve the contradiction between stamping formability and dent resistance of steel plates due to the lower strength and higher formability during stamping, as well as the advantages of increased strength after coating and baking. However, bake hardened steel can suffer from cracking problems in the stamping process. In this paper, the mechanical properties and stamping properties of the bake hardening steel were tested, and the production process was also analyzed. The results showed that the material has aged due to the long storage time, decreasing elongation. The main reason for stamping cracks was the reduction of the amount of oil applied to the material anti-rust oil. When the material was stored for a long time, the anti-rust oil on the surface of the steel plate volatilized, resulting in cracks in the stamping. Based on the above research, the material delivery time was strictly controlled. The cracks disappeared by supplementing and oiling the materials that had been stored for more than five months. The stamping performance of the bake hardening steel is improved.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.