晶粒度對析出硬化型不銹鋼強度的影響

Effects of Grain Size on the Mechanical Strength of the Precipitated-Harden Stainless Steel

藍元孝(Yuan-Shiau Lan)

指導教授 ： 趙志燁

國立屏東科技大學/工學院/機械工程系所/碩士(2016年)

摘要

高爾夫球球道木桿頭，在沒有特徵時間(CT)的限制下，設計皆朝向薄化(材料的極限)，因此，高溫熱處理的變異量，影響甚大。目前商用高爾夫球球道木桿頭，以455、465、17-4析岀硬化型不銹鋼為大宗，本文主要目的為探討455、465、17-4析岀硬化型在高溫熱處理晶粒大小對機械性質的影響，基本的顯微結構是麻田散鐵；且晶粒越大，與抗拉強度、降伏強度成反比、與硬度及延伸率無明顯差異，高溫熱處理溫度介於850-1050℃結果如下所示：
1. 455不銹鋼經不同高溫熱處理後，其抗拉強度、降伏強度與延伸率，分別介於140-164ksi、130-149ksi、10.7-11.5%之間。機械性質與晶粒大小之關係為，σY=125.4+101.6D-1/2，其中晶粒大小介於12.7至59.2μm之間。
2. 465不銹鋼經不同高溫熱處理後，其抗拉強度、降伏強度與延伸率，分別介於145-155ksi、140-143ksi、11.7-12.4%之間。機械性質與晶粒大小之關係為，σY=139.5+310D-1/2，其中晶粒大小介於44.5至50.4μm之間；另可觀察到晶粒大小變化不大，受來料(未熱處理)晶粒過大影響，顯示晶粒大小有上限。
3. 17-4PH不銹鋼經不同高溫熱處理後，其抗拉強度、降伏強度與延伸率，分別介於157-165ksi、142-150ksi、40-16%之間。機械性質與晶粒大小之關係為，σY=141.6+73.4D-1/2，其中晶粒大小介於14.0至38.9μm之間。
4. 以上結果符合Hall-Petch方程式，同時觀察，1770低合金鋼經不同高溫熱處理後，其抗拉強度、降伏強度與延伸率，分別介於151-158ksi、140-150ksi、11.0-11.2%之間。機械性質與晶粒大小之關係為，σY=139.2+46.4D-1/2，其中晶粒大小介於12.5至35.4μm之間，亦與上述結果相似。

關鍵字

晶粒大小 ； 析岀硬化型 ； 機械性質

並列摘要

The characteristic time (CT) of Fairway wood is not restriction resulting to thinning design. In addition, the Fairway wood would be usually producted by use of the pecipitated-harden stainless steel such as Custom 455, Custom 465 and 17-4PH. However, the grain sizes of the alloys would play an improtant role on the thinning design, of which being various high- temperature heated treatment. Therefore, the purposes of the present studies are focused on the effects of Grain Size on the Mechanical Strength of the Precipitated-Harden Stainless Steel. Some results are described as following:
1. The tensile strength, yield strength and elongation of Custom 455 stainless steel are between 140 to 164ksi, 130 to 149ksi and 10.7 to 11.5% respectively after heat treatment in different temperature. The relationship between Mechanical properties and grain size is σY = 125.4 + 101.6D-1/2, and the grain size is between 12.7 to 59.2μm.
2. The tensile strength, yield strength and elongation of Custom 456 stainless steel are between 145 to 155ksi, 140 to 143ksi and 11.7 to 12.4% respectively after heat treatment in different temperature. The relationship between Mechanical properties and grain size is σY = 139.5 + 310D-1/2, and the grain size is between 44.5 to 50.μm. Incidentally, Grain size can be observed just little change. Because grain size is too large impact (no heat treatment ), it has an upper limit.
3. The tensile strength, yield strength and elongation of Custom 456 stainless steel are between 157 to 165ksi, 142 to 150ksi and 40 to 16% respectively. The relationship between Mechanical properties and grain size is σY = 141.6 + 73.4D-1/2, and the grain size is between 14.0 to 38.9.μm.
4. These results are in compliance with Hall-Petch equation, and we observe the tensile strength, yield strength and elongation of 1770 low-alloy steel are between 151 to 158ksi, 140 to 150ksi and 11.0 to 11.2% respectively after heat treatment in different temperature. The relationship between Mechanical properties and grain size is σY = 125.4 + 101.6D-1/2, and the grain size is between 12.7 to 59.2μm. The result is the same.

並列關鍵字

grain size ； precipitated-harden ； mechanical properties

參考文獻

[2] 許勝安，「高爾夫球頭材質探究」，碩士論文，國立屏東科技大學，屏東，2014

[8] 曾秀鳳，「現今高爾夫球桿基本概念」，大學高爾夫學刊編輯委員會。

[15] 郭癸賓、趙志燁、何維華，「高爾夫桿頭合金材料機械性質之探討」，國立屏東科技大學、臺北市立大學運動器材科技研究所，華人運動生物力學期刊，第11期，第34-40頁，2014年10月。

[23] 郭癸賓、趙志燁，國立屏東科技大學，「高爾夫球桿頭擊球面厚度與特徵時間關係之探討」，嘉大體育健康休閒期刊第十三卷二期，158-168頁，2014年8月。

[3] 施聖瑋，「17-4PH和455不銹鋼焊接性分析」，碩士論文，國立屏東科技大學，屏東，2009