銅元素添加對鐵-17鉻-6鎳性質的影響

Effects of Copper Addition on the Mechanical Properties of Fe-17Cr-6Ni Alloy

10.6346/NPUST.2013.00235

張志銘

銅元素 ； 鐵鎳鉻不銹鋼 ； 機械性質 ； 麻田散鐵 ； Copper ； Fe-Ni-Cr stainless steel ； Mechanical properties ； Martensite

屏東科技大學機械工程系所學位論文

2013年

碩士

趙志燁

繁體中文

鐵-17鉻-6鎳-(0~3)銅合金主要係設計應用於高爾夫球頭材料，本文主要探討銅合金變化量對鐵-17鉻-6鎳合金之機械性質、硬度、以及顯微結構的影響，研究結果如下所示： 1.合金經1040℃固溶1小時處理後，其硬度分佈介於HRc30~20之間，隨著銅含量增加，硬度逐漸減少。降低固溶溫度至980℃，硬度則相對提高，分佈介於HRc40~20之間。合金經1040℃固溶1小時處理後，於480~540℃之間時效處理1~16小時，其硬度呈現典型時效分佈；除了當銅含量2.97%時，其硬度最高值發生約於1小時，硬度約達HRc23~25，其餘，隨著銅含量的降低，硬度最高值時間約至4小時發生，硬度分佈則介於HRc27~43。 2.合金經1040℃固溶1小時處理後，其抗拉強度為188～108ksi隨著銅含量增加，強度逐漸降低；降伏強度呈現二段分佈，銅含量小於1.6%，降伏強度介於135～145ksi，銅含量大於1.6%時，降伏強度則介於35~40ksi；其延伸率介於18～48%，隨著銅含量增加，延伸率逐漸增加。合金經1040℃固溶1小時+510℃時效4小時，其抗拉強度降為180～110ksi；降伏強度整體變化不大，惟銅含量1.16%合金，降伏強度由145ksi降至35ksi；其延伸率分別增加約10%。 3.SEM觀察顯示，合金基本結構為麻田散鐵組織，隨著銅含量增至1.64％以上，則可觀察到沃斯田鐵組織存在，銅含量2.97%時，沃斯田鐵約占30%。TEM觀察顯示：銅含量低時，麻田散鐵基地組織觀察到同方向區域組織分佈(類似次晶歷結構)，銅含量高時，則可觀察到沃斯田鐵與麻田散鐵具一定的方向關係，[001]m//[011]γ與(010)m//(111)γ。研究顯示：沃斯田鐵的存在，誘發特定的滑移現象，或改變合金硬化指數，導致高銅含量合金，降伏強度降低很多。 4. 鐵-17鉻-6鎳-(0~3)銅合金銅含量低時，機械強度與延伸率同時比目前商用17-4PH合金高10~15%，銅含量高時，則可提供6-4鈦之機械強度與304SS之延伸率的組合%。此合金系統深具有高爾夫球桿材料商業應用價值。

The Contents of Abstract in this Thesis: For the Golf-Head Club application, the Fe-17Cr-6Ni-(0~3)Cu alloys were designed and developed. The purposes of the present studies were focused on the microstructures and mechanical properties of these alloys. The major results are described as following: 1. Being heated at 1040℃ for 1 hour, the hardness of the alloys is in the range between HRc 30~20. With increasing the content of copper, the hardness of the alloy is decreased. Decreasing the temperature to 980℃ the hardness of the alloys is increased and of in the range between HRc 40~20. Moreover, during aged at 480~540℃ for 1~16 hours, the distribution of hardness would be a typical ageing peak profile. The time of max. peak would occurred at 1hour with highest copper content; and other copper content being increased at 4 hours. 2. The UTS of the alloys is essential in the range between 188~108ksi with decreased as copper content increasing. However, the yield strength of the alloy would be two-step distribution. The YS of the alloys with copper content below 1.64% is near 135~145 ksi, and being near 35~45 ksi with copper content above 1.64%. The elongation of the alloys is in the range between 18% and 48% which increases as copper content increasing. Being aged at 480℃-540℃, the strength of the alloys was decreased to 180~110 ksi. However the YS of the alloys with copper content is 1.16% was decreased from 145 ksi to 35 ksi, and elongation increased about 10%. 3. SEM examination indicated that the microstructure of the alloys was essential martensite phase. With increasing the copper content, some austenite phase was observed. When the copper content being 2.97%, the austenite is near 30%. In addition, TEM examination indicated that some sub-grain morphology could be found with lower copper content. And, increasing the copper content, some specific orientation relation between the martensite and austenite phase could be observed as [001]m//[011]γ, (010)m//(111)γ. It implies that the occurrence of austenite phase would enhance the different slip system or decreasing the harden coefficient, and resulting to the low yield strength when the alloy with the higher copper content. 4. Compared with the commercial materials, the present alloys would possess both strength and elongation. The alloy system would be high value on the Golf-Head Club. Keywords: Copper, Fe-Ni-Cr stainless steel, Mechanical properties, Martensite.