接上..........................
照片 ~8037內的黑色線段 充斥者致命的碳化物.
本帖最后由 leomet 于 2015-10-7 18:04 编辑
這塊420J2 我一蝕再蝕, 照了好幾百張照片.
平常看晶界碳化物似一短細線, 重蝕部位 可看到其實它昰薄片狀. 本帖最后由 leomet 于 2015-9-13 15:36 编辑
Cylinder liner 金相照片 本帖最后由 leomet 于 2015-10-7 18:02 编辑
上: 有芝麻點的是Steadite. 本帖最后由 leomet 于 2015-10-7 18:00 编辑
0.60%C 鋼, 冷鍛用鋼. Raw material for bike chain linkage.
Note the fineness of Ferrite grains. 学习了,太多了,好像学习不要哦
luoxz1990 发表于 2015-9-13 15:33
学习了,太多了,好像学习不要哦
好像学习不要哦 ?????????????????? leomet 发表于 2015-9-13 15:38 static/image/common/back.gif
好像学习不要哦 ??????????????????
太多了,感觉学习不完,打错了,嘿嘿,手机不好翻页
leomet 发表于 2015-8-26 19:15
Twin Boundary in 420 J2 stainless tool steel.
那些平形直線 可不是刮痕, 磨痕.
http://www.rclbbs.com/forum.php?mod=viewthread&tid=32665&extra=page%3D1&page=25
與這裡面twinning 双晶產生的機理, 兩者完全一樣. #35 carburized with different results. c.p. 0.80% 很好看,谢谢吴工的辛勤劳动,为大家分享。 伯龙马 发表于 2015-10-7 07:45
很好看,谢谢吴工的辛勤劳动,为大家分享。
甭謝啦!我只是愛現.
Taiwan No. 1 金相工, working with Taiwan No. 1 P/M tooling company: Edeex. 本帖最后由 leomet 于 2015-11-1 17:05 编辑
420 stainless steel in annealed condition.
孿晶界 碳化物
注意 "拔地而起"的碳化物.
Torsional fatigue fracture surface
本帖最后由 leomet 于 2015-11-2 09:07 编辑破斷面欣賞
This shaft broke after a test drive of only 100 Km mileage.
Material: SACM 450 or so, core: HRC25~28; Case: Nitrided. 假調質 Very poor microstructure. Continue, some SEM photos, 本帖最后由 leomet 于 2015-11-2 09:02 编辑
This part was made to experience a short service life for the reasons followed:
1. Fillet radius of 0.5 mm was too small.
2. Machining marks were not removed.
3. Very poor Q/T microstructure, leading to cleavage fracture surface.
4. and others.............
I am in English mode today. It is my
hope that you enjoy reading these photos. 本帖最后由 leomet 于 2015-11-4 18:31 编辑
This FT200 was complained to have a very poor cutting tool life..
Reason: too much carbide in cell boundary area. 本帖最后由 leomet 于 2015-11-4 09:50 编辑
2015-11-3 420 J2, Twin Carbide 再照 淺蝕後又拋光, 再重蝕, 所以 孿晶碳化物薄片有點碎裂.