滲碳參數與淬火硬化方式對鋼料表面硬化特性之影響

The Effect of Carburizing Parameters and Quenching Hardening Methods on Surface Hardening Characteristics for Steels

歐修齊(Siou-Ci Ou)

指導教授 ： 曾春風

國立虎尾科技大學/工程學院/材料科學與工程系材料科學與綠色能源工程碩士班/碩士(2015年)

https://doi.org/10.6827/NFU.2015.00052

摘要

本研究旨在探討不同滲碳參數與淬火硬化方式對JIS-S15C 與JIS-SCM415 二種常見滲碳用鋼料之硬度分佈、硬化深度、淬火變形量、磨耗性質及顯微組織的影響；並尋找滲碳鋼種在滲碳高週波感應淬火後淬火變形量最小，而磨耗性質最佳之高週波參數。最後與傳統之滲碳直接淬火比較其淬火特性與淬火變形的改善情形。
實驗結果顯示，JIS-S15C 與JIS-SCM415 二種鋼料試棒於各碳勢滲碳後，JIS-S15C試棒顯示出較JIS-SCM415者為深之滲碳深度，但在直接淬火後JIS-SCM415則呈現出較JIS-S15C深0.1~0.2mm的硬化深度。在硬度上，JIS-SCM415之表面硬度較JIS-S15C硬HV20~60。滲碳淬火後之JIS-S15C與JIS-SCM415鋼料表面硬度隨著碳勢的增加而增加；在各不同碳勢下，二種鋼料進行滲碳高週波感應淬火之表面硬度皆達到較滲碳直接淬火者高約HV100之超硬度(約HV910)，且藉由高週波輸入功率與線圈速度的變化可改變硬化深度。在偏轉量方面，滲碳直接淬火試棒之單位長度最大偏轉量隨著滲碳碳勢的增加而增加。滲碳高週波感應淬火之試棒的單位長度最大偏轉量，隨著輸入功率增加或線圈移動速度下降而增加。試棒在滲碳後進行高週波感應淬火硬化可大幅改善滲碳直接淬火硬化所產生之變形問題。對二種滲碳鋼而言，輸入功率固定時，試棒單位長度最大偏轉量改善幅度隨碳勢的增加而增加；滲碳碳勢固定時改善幅度也隨輸入功率的下降而增加； JIS-S15C改善幅度最大可達67%~82%，而JIS-SCM415改善幅度則可達85%~93%。藉由高週波輸入功率與線圈速度的改變，可使鋼料顯微組織產生差異，進而影響淬火變形量與磨耗性質；若採用適當的輸入功率與線圈移動速度，可使滲碳高週波感應淬火之鋼料組織微細化，且殘留沃斯田鐵量較少，進而使其變形量與摩擦係數達到較滲碳直接淬火者為低之狀態。

關鍵字

滲碳參數高週波感應淬火 ； 淬火變形量碳勢 ； 線圈移動速度輸入功率

並列摘要

The purpose of this study is to investigate the effect of different carburizing parameters and quenching method on hardness distribution, hardening depth, quenching distortion, wear resistance and microstructures for two common carburizing steels which are JIS-S15C and JIS-SCM415 respectively. The study also looks for the optimum parameters that can reduce the quenching distortion and increase the wear resistance of the steels specimens which were high frequency induction hardened after carburizing. Finally, comparisons of quenching characteristics investigation and quenching distortion improvement between high frequency induction quenching and conventional direct quenching were made for carburized steels.
The result indicates that JIS-S15C shows deeper carburizing depth than JIS-SCM415, but shallower 0.1~0.2mm hardening depth after conventional direction quenching at every carbon potential for both of carburizing specimens of JIS-S15C and JIS-SCM415. In the hardness, the surface hardness of JIS-SCM415 is more than that of JIS-S15C about HV20~60. Furthermore, the surface hardnesses of carburized specimens were increased with the carbon potential increasing. Both of JIS-S15C and JIS-SCM415 steels specimens form a super-hardness through high frequency induction hardening after carburizing at different carbon potential, the super-hardness (about HV910) of high frequency induction quenching is higher than that of direction quenching about HV100 after carburizing, and it can change the hardening depth by controlling the input power and motion velocity of the induction coil. The maximum deflection of unit length of the direct quenching for carburized specimen increases with the carbon potential increasing; the maximum deflection of unit length of the specimens through high-frequency induction quenching after carburizing is increased with the input power increasing or the motion velocity of the induction coil decreasing; the problem of quenching distortion of the specimens through high-frequency induction quenching after carburizing is remarkably improved. For the two kinds of steels, the improvement % of maximum deflection of unit length for specimens will increase as carbon potential is increased at constant input power, and the improvement % will also increase as input power is decreased at constant carbon potential. The improvement % varies with the parameters, the maximun improvement % of JIS-S15C is up to 67%~82%, and the improvement % of JIS-SCM415 is up to 85%~93% at different carbon potential. The result microstructures are different by changing input power and motion velocity of the induction coil, and which thereby affect the quenching distortion and the wear resistance. By using proper input power and motion velocity of the induction coil, the microstructures of specimens through high-frequency induction quenching after carburizing would become more refiner, and the retained austenite is less. Furthermore, the quenching distortion and the friction coefficient for the specimens through high frequency induction quenching after carburizing would be lower than the specimen which is direct quenching after carburizing.

並列關鍵字

carburizing parameters ； quenching distortion ； high frequency induction quenching ； carbon potential ； input power ； induction coil

參考文獻

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