- 學位論文
不同熱處理及生產製程對於塑膠模具鋼之顯微組織與機械性質研究
Study on the Microstructure and Mechanical Properties of Plastic Mould Steel under Different Heat Treatments and Manufacturing Processes
摘要
模具鋼用途甚為廣泛，從航太產業、汽車產業、鋼鐵產業、建築產業和塑膠產業等，乃至一般生活日常產品皆會有所使用，如飛機零件、汽車外殼、塑膠射出成形等。近年來隨著工業進步，模具鋼生產成本逐漸降低，但產品品質及生產效率皆逐漸提高。 本次研究材料為兩種不同型號之塑膠模具鋼，分別為STAVAX和GPX-1。其中，STAVAX模具鋼研究方式為相同淬火溫度(1030℃)及四種不同回火溫度(200℃、250℃、500℃、520℃)，而GPX-1模具鋼研究方法則為透過不同生產製程(傳統鍛造及3D鍛造)及不同熱處理製程(油淬、水淬、回火、退火)，並各自觀察其顯微組織與機械性質差異。本次主要透過光學顯微鏡(OM)、掃描式電子顯微鏡(SEM)及穿透式電子顯微鏡(TEM)來觀察其顯微組織，機械性質測試數據則是由萬能材料試驗機、維克式微硬度計及衝擊試驗機來獲得。經熱處理後，兩種模具鋼基底相轉變為麻田散鐵組織，隨著回火溫度增加，鋼材降伏強度及抗拉強度會隨之下降，然而析出之碳化物尺寸卻不會隨著回火溫度改變而使其明顯增大或縮小，接著透過穿透式電子顯微鏡可觀察發現本次研究之兩種模具鋼皆富含鉻(Cr)合金原素碳化物，最後經由電子背向式散射繞射儀(EBSD)得知兩種塑膠模具鋼之M23C6碳化物比例、晶格扭曲、晶粒角度及晶界角度。
並列摘要
Plastic mould steels have a wide range of applications, spanning industries such as aerospace, automotive, steel, construction, and plastics, as well as everyday products like airplane parts, car bodies, and plastic injection molding. In recent years, with industrial advancements, the production costs of mould steels have gradually decreased, while the quality and production efficiency of the products have steadily improved. This study focuses on two different types of plastic mould steels, designated as STAVAX and GPX-1. For STAVAX mold steel, the research approach involves using the same quenching temperature (1030°C) and four different tempering temperatures (200°C, 250°C, 500°C, 520°C). For GPX-1 mold steel, the research method involves different production processes (traditional forging and 3D forging) and different heat treatment methods (oil quenching, water quenching, tempering and annealing), with observations on their microstructures and mechanical properties. The microstructures were observed using Optical Microscopy (OM), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM). The mechanical property test data were obtained using a Universal Testing Machine, a Vickers microhardness tester, and an impact tester. After heat treatment, the base phase of both mould steels transformed into martensite. As the tempering temperature increased, the yield strength and tensile strength of the steels decreased. However, the size of the precipitated carbides did not significantly change with varying tempering temperatures. By TEM observation, it was found that both types of mould steels studied are rich in chromium (Cr) alloy element carbides. Finally, through Electron Backscatter Diffraction (EBSD), the proportion of M23C6 carbides, lattice distortion, grain angles, and grain boundary angles of the two plastic mould steels were determined.