The Effect of Corrosion in the Salt Atmosphere and Wear Behavior on the Strength Reduction

• Main Authors: Wen-Fung Chang, 張文峰
• Other Authors: Yuan-Ching Lin
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/98dmbn

碩士 === 國立臺灣科技大學 === 機械工程系 === 99 === This thesis is focused on the corrosion strength of wire ropes after smearing on different lubricants in different salt concentration atmosphere. Also, effects of protective lubricants on wires passing through pulleys and the strength decay phenomena are discussed. Electrochemical potentiodynamic polarization curve shows that for non-lubricated wires of 3.5% NaCl, the corrosion current (Icorr) was higher with a lower corrosion potential (Ecorr) than 5% NaCl. The salt-spraying test results reveal that in 3.5% and 5%NaCl, the surfaces of non-lubricated wires and wires with85W/140 gear oil cause more serious corrosion by increasing test days. Non-uniformity of the smearing lubricants causes strength slower reduction by increasing test days. Moreover, surfaces with wire rope oil have the best protective ability. The tensile test results show that in 3.5% and 5%NaCl, the strength rapidly decline with increasing test days for non-lubricated wires and wires with 85W/140 gear oil. In addition, the oxygen and chlorine elements are found on the fracture surface on the fifth and the ninth days. However, elongation is decreased for ductility decrease with increasing test days. For lubricated wires without uniform smearing cause the strength decrease with increasing test days. Moreover, wires with wire rope oil have the best strength. Under different load conditions, the results show that under the load of 2kg, non-lubricated wires and wires with 85W/140 gear oil have more serious decay on ultimate tensile strength (UTS), and it is not happened for wires with wire rope oil and grease. Under the load of 6kg, except wires with wire rope oil, there is no existing boundary layer between contact surfaces, and which causes UTS to decrease. Under different sliding distance conditions, at the sliding distance of 4.5km, non-lubricated wires and wires with 85W/140 gear oil have more serious decay on UTS, and wires with wire rope oil and grease do not have significant decay on UTS. At the sliding distance of 13.5km, except wires with wire rope oil, there is no existing boundary layer between contact surfaces, and which causes UTS to decrease.