Oxidation or Nitridation Behavior of Pure Chromium and Chromium Alloys Containing 10 mass%Ni or Fe in Atmospheric Heating
The oxidation or nitridation behavior of pure chromium and chromium alloys containing 10 mass%Ni or 10 mass%Fe in atmospheric heating was investigated in the temperature range of 1073 to 1373 K. The formation behavior of the outer oxide phase of Cr2O3 and its growth kinetics in both chromium alloys was very similar to that of pure chromium. The nitride layer with the Cr2N phase was formed beneath the oxide phase at temperatures above 1273 K in pure chromium. Marked internal nitridation with the formation of the Cr2N phase was observed in the Cr-10 mass%Fe alloy, while the formation of Cr2N was negligible in the Cr-10 mass%Ni alloy. Neither Ni nor Fe were detected inside the Cr2O3 phase, and was enriched in the subsurface layer between the oxide layer and the base alloy in a respective alloy. The Ni-enriched layer in Cr-10 mass%Ni alloy had a relatively narrow width, but a very high concentration of Ni compared with the Fe-enriched layer formed in the Cr-10 mass%Fe alloy. [doi:10.2320/matertrans.47.2540]
VACUUM-ARC CHROMIUM COATINGS FOR Zr-1Nb ALLOY PROTECTION AGAINST HIGH-TEMPERATURE OXIDATION IN AIR
The effect of vacuum-arc Cr coatings on the alloy E110 resistance to the oxidation in air at temperatures 1020 °С and 1100 °С for 3600 s has been investigated. The methods of scanning electron microscope, X-ray analysis and nanoindentation were used to determine the thickness, phase, mechanical properties of coatings and oxide layers. The results show that the chromium coating can effectively protect fuel tubes against high-temperature oxidation in air for one hour. In the coating during oxidation at T = 1100 °С a Cr
Evaluation of Impact of Yarn Count and Stitch Length on Pilling, Abrasion, Shrinkage and Tightness Factor of 1 ? 1 Rib Cotton Knitted Fabrics
This study investigates the impact of yarn count and stitch length of 100% cotton knitted fabrics. 1 × 1 ribs structured fabrics were used in this research work. The stitch length 2.50 mm, 2.52 mm, 2.60 mm, 2.70 mm, 2.80 mm and 2.96 mm were used of the yarn count of 26Ne, 28Ne and 36Ne. The areal densities of the grey fabrics were in various amounts. The impacts of yarn count and stitch length were measured concerning pilling resistance, abrasion resistance, and shrinkage and tightness factor. The result showed that the fabric pilling grade decreased while number of cycle increased. Abrasion resistance decreased but length wise shrinkage increased despite the fact that the stitch length increased. The results also exposed that the tightness factor of the fabric increased with the increase of the stitch length in both dyeing and washing state and finished state compared to grey state for the yarn count 26Ne and homogeneous result not found for yarn count 28Ne and 36 Ne. Evaluation of Impact of Yarn Count and Stitch Length on Pilling, Abrasion, Shrinkage and Tightness Factor of 1 × 1 Rib Cotton Knitted Fabrics