经典的金相组织照片(会员"leomet"的合集)

leomet

Near eutectic,  white cast iron
rod-like eutectic mixture of carbide and iron (rods)

leomet

AISI 310, heat-resistant steel. 枝晶界碳化物
As-cast : carbide particles in dendrite arm boundaries.
solution treated at 1050 C and quenched in water.

leomet

Nowhere else but this forum can you find such a wealth of quality photos (metallographic micrographs).

    A tooling was scrapped before shipping to customer because of dimensional change.
    The swelling with time was caused by too much R.A. in the matrix.
    This is an age-old problem but you still encounter it once in a long while.
   
    Carbide phase is tinted pale blue to red-purple for sharper contrast--easier distinction of R. A.
which is now white and pale yellow in the matrix, mostly. Darker area in the matrix is T.M.
R.A. is brighter because those areas are flatter and more reflective to lncident light.
   
     Two of these photos are in 800x600 format for your visual delight.

leomet

D-type graphite for glass molds, aiming to delay
formation of “heat checks” on glass-mold surfaces.

The proper coloring of carbide was obtained by  a lot of hard-work (different times of etching+tinting),
------ and  a bit of luck as well.

hongweijian

SKD 11锻前的共晶碳化物经锻打被击碎，都成带状组织分布

leomet

Two cold work tool steels.   Annealed condition: colored carbide particles in the white matrix of ferrite.
Carbide tinted.  Note the network of secondary carbide in the matrix.

leomet

189# leomet

A cold work tool steel, same as that shown in #185, quenched and deep-frozened and tempered.
Carbide particles in the matrix of tempered martensite.
Compare to #185, R.A. is now gone and nowhere to be found.  

tanggang3008

彩色金相就漂亮，我一直想做，就是每天太忙没时间呀！哈哈

leomet

191# tanggang3008

不難, 只是非常耗時, 有時 5, 6 次才會碰上一次滿意的色彩.

leomet

190# leomet
Same cold work tool steels as above (#189). Matrix is tinted while Carbide is unaffected.
Note the network of carbide particles in photo 195~225. These network of carbide, if not completely go into the solution of austenite before quenching. Traces of it will remain in the grainboundaries after quenching. Although it might not be seen under O.M., it  put the toughness of the steel in harm's way.

leomet

193# leomet
Metallographic micrographes for a glass mold.
Ti is usually added to encourage formation of finely dispersed D-type graphite
which provide the mold with a longer thermal fatigue life.
Orange phase in the cell boundaries is Steadite. Sharp, pointed spikes of steadite
are very harmful to thermal fatigue life
because they are stress-risers and thus, initiation sites for microcracks.

leomet

194# leomet
A hot work tool steel (~ H11), Q/T.

leomet

195# leomet
FT 300  grey cast iron with steadite tinted pink.

xiaqing

30# leomet

这是亚共析钢等温淬火后的相组织图吧？

leomet

Cold work steel  hardened, subzero treated and tempered.
carbide phase is tinted pink and purple.

leomet

AISI 4340 casting, 550C x 2 hr  tempered.
Focusing on the area near interdendritic shrinkage.
Note the carbide film in-between dendrite arms.

leomet

AISI 4340 casting, same as # 199
Showing dendritic segregation. Dark areas are rich
in C% and alloying elements.
So you will often find Hi C Martensite, R.A., inclusion, and even carbide in
these areas in as-cast condition, and also in continuous cast and rolled steel
rods without homogenization annealing or normalizing.

leomet

My footprints on the sand of time of my career as a metallurgist.

178# leomet
Solution treated (K in 310). Some of them were aged (Others). As-cast (The last one)

hlfhljj

请教下各位专家在测量脱碳层深度时，有部分贫碳，同时过渡区不明显。按照什么样的标准测量？

leomet

199# leomet
Alloy grey cast iron. Annealed at 900C. Most of the pearlite is spheroidized.