The Study of Thermal Forged Laminar Composites

• Main Authors: Jung Ting -Chen, 陳榕庭
• Other Authors: Weite Wu
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/77109065945288653575

碩士 === 義守大學 === 材料科學與工程學系 === 88 === This research studies the microstructure of middle carbon steel, S45C, and mild steel, JISG 3301, composites after forging and folding at high temperature. In order to increase the connected area of the S45C and JISG 3301, I combine them by Spot welding the edges of the two materials. At last, observe the changes of the material’s microstructure were observed after forging and folding the semi-combined material to 3, 7 and 15 layers. In order to combine two different materials at high temperture, first, I make the two steels reach near fusing condition. If the temperture is not appropriate, the material will form crack around the side of the sample. And the distribution of combined layer will not good neither. When the forging times and layers increase, its grain structure will become finer. But if the forging times are too much, the original grain will become longer and thinner. When grain growth happen, it will form several grains. Different grain surface will apart because of large cold draw, and its grain won’t grow. Although it can become very fine grain structure, this condition is different from the original grain condition. In the condition of metal flow of flow , when the strain is high, the flow stress will become higher, then the grain will become finer. In the condition of hardness, the fewer the combined layers are, the lower the material’s hardness will be. But when the forging times increase, the material’s hardness will be lower. While the forging amount increase, the influences of forging will be revealed, and the hardness of the material will be higher.