Nitrate concentrations of automatic polishing machine specimens of anti corrosion weightlessness and light

The specimens with low carbon steel ( C < 0。 3%) The piece is made. Sample corrosion weightlessness degree is decided by polishing the weight difference of the sample. The brightness of the light reflection on the surface of the test. With light reflectivity of 100% mirror as a benchmark, with island ferry UV - The type 240 uv-vis spectrophotometer testing, 600 nm to 800 nm wavelength range. H2SO432 %, HNO38 %, T = 100 Celsius, when T = 2 min determination of phosphate concentration by 40% 65% when the specimens of erode weightlessness and light reflectivity change status. * * * * * * in chemical polishing liquid one of the main components of mucous membrane formation, it not only improved the polishing liquid viscosity, more major is that it can dissolve and corrosion of iron ion on the polishing of the surface of the metal forming sticky multi-core ( The multiple iron) * * * * * * ( Here is * * * * * *) * * * * * * * * * membrane, that is, commonly known as the mucous membrane. The mucous membrane can be used as metal * * * * * * and solution diffusion barrier layer between ontology, it's on the metal surface bulge thin, * * * * * * * * * * * * by the metal surface bulge to the solution of the ontology through the diffusion layer diffusion speed, while the metal surface cavity mucous membrane thickness, * * * * * * * * * * * * diffusion speed is slow, to dissolve bulge priority, so repeated to reach the surface of the leveling effect. * * * * * * concentration is too low, the polishing liquid viscosity is low, not easy to form a mucous membrane, parallel to the surface of the whole is poor, poor polishing effect; * * * * * * concentration is too high, the polishing liquid viscosity is too large, the polishing speed slow, although can achieve leveling effect, but the matt surface, also affect the brightness. * * * * * * best concentration was 50% ~ 54% when polishing effect. In addition with the automatic polishing machine polishing liquid in the * * * * * * the increase of concentration, solution viscosity, slows down the * * * * * * * * * * * * from the metal surface to the solution of the ontology diffusion, resulting in the weightlessness of iron gradually reduced. Automatic polishing machine * * * * * * the influence of the concentration of specimens on the corrosion weightlessness and light reflectivity metal corrosion weightlessness curve can be seen, as the polishing liquid * * * * * * in the increase of concentration, the amount of dissolved iron increase gradually, but the increasing amplitude decreases. This suggests that * * * * * * mainly oxidation effect in polishing, it determines the generation of oxidation film on the metal surface, increases with the concentration of * * * * * *, oxide film formation rate is accelerated, the weightlessness is less metal. In addition, along with the increase of concentration of * * * * * *, loss of weight of the metal increases gradually, and the extent of increase gradually strengthened, it comes down to * * * * * * solution effect of oxide film. Low concentration of * * * * * * and * * * * * * with high concentration corresponding to the steel specimens of high brightness, this is due to the high concentration of * * * * * * and low concentration of * * * * * * ensures that the dissolution rate of oxide film is greater than the rate of production, so as to achieve light effect. But, if the * * * * * * concentration is too low, not easy to form oxidation film, light effect. * * * * * * concentration is too high, speed too fast, the dissolution of oxide film will cause metal dissolved by the inhomogeneity of * * * * * *, make the metal surface brightness. Automatic polishing machine * * * * * * the influence of the concentration of specimens on the corrosion weightlessness and light reflectivity specimens of weightlessness and light reflectance curve along with the change of water content in liquid polishing, in order to obtain the best polishing effect, polishing liquid water content should be controlled as far as possible in the low concentration range, such as 7% ~ 9%. As the polishing liquid water levels continue to rise, mucous layer is damaged, * * * * * * * * * * * * in the metal surface of convex and concave in diffusion velocity difference decreases, and deterioration in leveling sex, brightness. For automatic polishing machine polishing liquid temperature and polishing time iron corrosion weightlessness and reflectivity results show that the influence of metal weightlessness curve along with the change of temperature is a typical rate temperature curve, namely with the increase of temperature, metal dissolution rate increased gradually. Temperature is too low, the quantity is little, the dissolution of metal polishing liquid in * * * * * * * * * * * * concentration is low, polishing liquid viscosity is low, not easy to form a viscous liquid membrane, therefore polishing polishing effect is poor; Temperature is too high polishing liquid viscosity, easy to cause on the surface of the metal corrosion, brightness is falling fast. Therefore, polishing temperature should be controlled between 20 ℃ and 40 ℃. In the beginning, as the extension of polishing time, the corrosion of the metal weight quickly. In 1 min ~ 2 min, weightlessness curve become more smooth, and the corresponding plate has the most brightness. This is due to the polishing rate controlled by diffusion, the diffusion balance. When polishing the time extended, the weightlessness of the metal and accelerated rapidly, has had the corrosion of metal surfaces, brightness down, so the general polishing min 1 ~ 2 min.