- Aug 20 Mon 2012 20:52
D / E 形石墨 graphite
- Aug 20 Mon 2012 15:41
晶界上的異物 與此同理
- Aug 12 Sun 2012 12:50
疲勞破斷面 軸心
外面較平滑的一圈是緩裂區(海灘紋), 內部為驟裂區, 面積還蠻大的 表示所承受應力不小 or 材料強度太低 . 這個例子是材料強度太低, 因為沒做調質熱處理, 心部是退火狀態的波來鐵+肥粒鐵. 破裂起始點是整個外圈變徑處沒做內圓角處理. 轉角尖銳引起的應力集中. 設計者未受機械設計的訓練, 使用錯誤嘗試法來製造此機件.
- Aug 01 Wed 2012 17:50
鑄鉄高週波淬火 波來鉄%要夠多
- Jul 21 Sat 2012 22:21
鑄件表面氣孔
- Jul 17 Tue 2012 23:56
調質淬火後均勻的麻田散鉄組織
- Jul 15 Sun 2012 12:18
- 機牀軌道 雞爪紋 (收縮裂紋)
- Jul 15 Sun 2012 12:08
通寶 未熔
鑄造廠用的"砂心撐" 台語叫"通寶". 低碳鋼做的, 熔點~1500C. 鉄水溫度不夠高時熔不掉, 加工後就像這樣. 鑄件就報廢了.
- Jul 11 Wed 2012 22:03
這種調質組織, 真夭壽!
JIS S55C; Darn lousy Q/T microstructure. Mostly fine Pearlite rather than T.M. required by Q/T. Insufficient Austenization time (leads to) → tiny grain size → poor hardenability → fine Pearlite. Also, oil-quenching was a wrong choice. This AISI 1055 should have been quenched using water-based quenchant to obtained enough amount of Martensite with ease. Quenching severity of oil is not good enough for 1055 to harden successfully.
