不銹鋼之摩擦鑽孔加工及其材料強化研究

A Study of Stainless Steel by Friction Drilling Processing and Materials Strengthening

陳彥良(Yen-liang Chen)

指導教授 ： 顏炳華

國立中央大學/工學院/機械工程學系/碩士(2008年)

摘要

本研究係以摩擦鑽孔的方式同時藉由不同的流體冷卻，產生熱處理作用，達成孔壁材料強化之目的。摩擦鑽孔的加工方式主要是利用刀具的高速旋轉，當刀具接觸材料時，相互摩擦產生熱能，加工區瞬間達到熔融溫度時穿刺材料，於材料處在高溫狀態時，快速將刀具提升，形成一個孔洞的新型成形方法。完成加工後在材料高溫尚未下降的同時，以不同的流體進行冷卻，達到熱處理效果，形成一連續製程。
本文研究以 AISI304 不銹鋼為材料進行摩擦鑽孔加工，同時使用不同的冷卻流體，包括純水、淬火油、氮氣和空氣，搭配所需之加工參數，並配合不同的冷卻延遲處理時間進行實驗。實驗結果主要針對加工後孔璧的表面變化、孔真圓度、表面粗糙度、表面硬度、表面硬化層厚度、孔襯長度等進行觀察與比較，以獲得孔加工的較佳參數條件與表面品質，並探討經由此製程加工後其孔壁材料強化之可行性。
研究中發現，無論以空氣、氮氣、純水或淬火油冷卻時，當轉速達3600rpm 時所得到的孔壁面效果較佳。若以四種流體相互比較時，空氣和氮氣雖然在粗糙度、真圓度的所得的效果較佳，但是硬化層厚度和硬化層硬度不佳。而以純水冷卻所得的結果方面，雖然硬度和硬化層較空氣及氮氣冷卻所得的結果較佳，但再和淬火油相比較下，仍以淬火油之結果較符合後續加工之需求。當冷卻延遲時間在 0.2s 時，材料可以得到充分的緩衝，無論是孔壁的粗糙度、 硬化層厚度及硬度都能有顯著的改善。
本研究成功開發摩擦鑽孔製程結合不同冷卻方式，達到孔壁表面強化之效果，可省略熱處理之製程，進而降低生產成本，提升原材料機械性質。

關鍵字

摩擦鑽孔 ； 材料強化 ； 不銹鋼 ； 硬化層 ； 孔襯 ； 延遲處理時間

並列摘要

This research is using friction drilling to get a hole, then using different fluids to cool the hole wall simultaneously. The friction drilling processes are using a high speed rotating conical tool to penetrate a thin workpiece and create a bushing without generating chips. After completing the friction drilling processes, the material is still on high temperature, and then use different fluid to cool the hole wall simultaneously in order to get heat treatment results.
This research is using friction drilling to get a hole, the workpiece is AISI 304 stainless steel, and using different fluids to cool the hole wall simultaneously, including pure water, quenching oil, air, and nitrogen gas. Collocating the working parameter we necessary, and different cooling delay time experimenting with friction drilling. We observe the hole wall after the friction drilling, hole roundness, hole surface roughness, surface hardness, bushing length, and hardness layers depth in experiments. In order to get the better parameters of the hole drilling and surface quality.
The results of experimental show that cooling the hole whenever using pure water, quenching oil, air, and nitrogen gas, it can get the best surface roughness when the rotating speed is 3600 rpm. Although the results in air and nitrogen gas are having better effects in roughness and roundness, but their hardness layer depth and hardness aren’t better than pure water and quenching oil. After friction drilling using quenching oil cooling, the hole is better than the other three. When the cooling delay time is 0.2 second, the workpiece get a protecting no matter what surface hardness, hardness layer depth and hardness are having the eminent improvement.

並列關鍵字

Bushing ； Hardness Layer ； Stainless Steel ； Materials Strengthening ； Friction Drilling ； Delay Time

參考文獻

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