Corrosão e desgaste químico das lâminas de aço utilizadas no desdobro da madeira

Abstract

The objective this work was to evaluate the chemical waste provoked by the wood on the sheets of steel used in the making of the mountains and cut tools. It was certain the correlation between the chemical waste and the extractive soluble in cold water, hot water and in the sequence toluene and ethanol content. Two types of steel and twenty-seven species different from wood were used. The corrosive agent, constituted of 50 g of fresh sawdust (moist) mixed to 50 ml of distilled water, it was prepared and placed inside of the plastic box, hermetically closed, on the samples of steel, which were totally immersed. The box was placed in a water bath pre-heated to 75°C, that the medium temperature of reaction is considered, that affects the sheet of the sawblade in operation. This group was operated to 80 rotations per minute (rpm). The time of reaction was of four hours. After that time the corrosive agent was discarded and the samples were washed, dried and weighed. At the end, each sample was processed by a total period of forty hours. The chemical waste was evaluated by the weight difference suffered from beginning at the end of the experiment. For the results it was observed that the Eucalyptus tradryphloia and the Eucalyptus phaeotricha the species that provoked were, respectively, the largest and smaller chemical waste for the two types of steel appraised. Great variation exists in the chemical waste due to the effect of the species. The corrosion and chemical waste are especially related with the quality of the material solved in ethanol. The 1070 steel were more attached than the 6170 steel.