I am looking at replacing a current pin made of 41L40 steel with one made from 10B21 steel. It needs to be hardened to 30-40 Rockwell C. Is this safe change? I want to change from a machined component to one that is cold headed but I don't know much about cold heading steels. This pin is 1 inch long with a diameter of .175"
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10B21 Steel Hardening 2
- Thread starter yanish
- Start date
Cold heading the pin will work harden the head. You need to check in a good steel book about what you can harden the 1021 to, safety should not be a problem with the exception that the shaft of the pin is much more brittle as you go up in hardness.
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1
- #3
In looking at your information, I have the following suggestions:
1) I would suggest that you order the material to a cold heading quality. This will
specify cleanliness, surface defects and other important factors. You may find that
for cold heading, you do not want a boron treated steel. This would cause you to
look at other alloys.
2) 10B21 may not be a standard grade. I would suggest that you use 1040 which is a
standard grade. This would eliminate an alloying charge and you would have
several sources to choose from.
3) The hardenability and depth of hardness of 10B21 should be OK for a hardness of
30-40 HRc. I would suggest that you get some data from your supplier. This
should include mechanical properties for the material at those hardnesses and the
data should include impact strength. My concern would be the tempering
temperature and what kind of tensile, yeild, elongation, and impact strengths you
need. This may change the alloy you need.
Hope this helps.
1) I would suggest that you order the material to a cold heading quality. This will
specify cleanliness, surface defects and other important factors. You may find that
for cold heading, you do not want a boron treated steel. This would cause you to
look at other alloys.
2) 10B21 may not be a standard grade. I would suggest that you use 1040 which is a
standard grade. This would eliminate an alloying charge and you would have
several sources to choose from.
3) The hardenability and depth of hardness of 10B21 should be OK for a hardness of
30-40 HRc. I would suggest that you get some data from your supplier. This
should include mechanical properties for the material at those hardnesses and the
data should include impact strength. My concern would be the tempering
temperature and what kind of tensile, yeild, elongation, and impact strengths you
need. This may change the alloy you need.
Hope this helps.
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1
- #4
geoffriong
Automotive
We cold form, carburize and austemper pinions for automotive starters with great success using 10B21. Carburized, austempered surface hardnesses are typically in the 54-56 HRC range, while core hardness is 41-46 HRC. The parts have excellent wear resistance and great impact properties. Our parts are basically tubular in shape have dimensions that are roughly 1" in length by 1" in diameter with 0.25" wall thickness. The spheroidize anneal prior to cold forming is absolutely critical.
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