Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-31 Cooperative journals: 《中国腐蚀与防护学报》
Abstract: The corrosion performance of Ni free and Mn alloyed high nitrogen austenitic stainless steels (HNSSs), including uniform corrosion, intergranular corrosion, crevice corrosion, pitting corrosion and repassivation,was investigated by means of immersion test and electrochemical test. The effect of cold work and sensitization treatment on the microstructure, characteristic of passive film and corrosion resistance of the HNSSs was examined. It was found that the solution-annealed (SA) HNSSs had much weaker resistance to uniform- and intergranular- corrosion compared to the SA 316LSS. The sensitization- treatment (ST) hardly affected the uniform corrosion resistance of all the steels, but resulted in rapid degradation of the resistance to intergranular-corrosion, especially for the Mo free HNSSs. The SA HNSSs had a better resistance to crevice- and pitting- corrosion than the SA 316LSS, in particular the Mo bearing HNSSs. The ST degraded the resistance to crevice- and pitting-corrosion of the HNSSs. The cold work degraded the pitting-corrosion resistance of the HNSSs in chloride- containing solutions through thinning the passive film and decreasing the stable oxides in the passive film, but it improved the repassivation ability of the HNSSs. The ST-induced precipitation of χ phase degraded the corrosion resistance and repssivation ability of the HNSSs, and such degradation became aggravated with increasing cold work degree. Furthermore, the relevant corrosion mechanism is also discussed.
Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-31 Cooperative journals: 《腐蚀科学与防护技术》
Abstract: none
Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-31 Cooperative journals: 《腐蚀科学与防护技术》
Abstract: none
Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-31 Cooperative journals: 《材料研究学报》
Abstract: Polyurethane coatings with two kinds of sillitin, i.e. M type and Z type sillitin respectively as filler were prepared and sprayed on hot dip galvanized steel sheets. The coatings exhibited better mechanical properties than the simple polyurethane coating, i.e. the wear resistance and the hardness of the polyurethane coating may be enhanced by 57.1% and 14.5%, as well as 85.7% and 41.8% for the addition of M type and Z type sillitin respectively. The coatings with the two types of sillitin exhibited also better corrosion resistance. The reason is that two types of sillitin are of a special structure composed of micro- sized granular silica and nano- flake kaolin clay, and the sillitin possesses high amount of nanoflake, which may be beneficial to the enhancement of the permeation resistance and mechanical properties of the coatings.