More need not be always good. I had one lot of high chrome iron castings cracking during heat treatment. The lab was convinced that Ni and Mo are friendly elements and could cause no harm in service. The Moly content was about 0.4% higher than specified and Ni about 0.8%. ( Obviously a mixup in...
I maintain Silicon 0.5-0.7%. This is even high but we have no control as it depends on Si content in high carbon ferrochrome alloy.
Response to heat treatment is better with the lower Silicon content.
Going bankrupt is more common than catching fire. I have been through that road. After 20 years I had to close shop and now undertake consulting for past 10 years. No regrets though.
Post printing cleaning we apply a epoxy coat on the pattern for easy release of the mould.
I have used PLA, PetG, ABS etc. for making patterns or core boxes .
We are now in the process of selecting a metal 3D printer (DLMS) technology.
You can consider using 3D printing pattern and core boxes . I have been doing this for about 4 years. Alternately you could use a 5 axis CNC router for wooden pattern and core boxes.
Manganese steels do not need any deoxidizers. The high Manganese and Carbon content prevent any gas related defects. Do not exceed your tapping temperature beyond 1480C. If you have left the metal long in the furnace or have wet ladles, gas can be picked up.
If need be add a mixture of Al And...
I agree it is poorly designed product. I would suggest bracing the cracked arm to the main rim using bolts and nuts.
Welding or using a Loctite is not helpful.
SGal,
Very interesting experience you have. MST handbook was the bible for us young metallurgists in 1970's. I come from the other side of the world, where Mittal started his steel journey. They were steel scrap traders in Calcutta.
I work in a steel foundry and getting quality steel scrap is...
It is nearly impossible to convince them. According to them CF8 castings cannot be repair welded (This is just one example)!!. Producing the standards and industry practice did not convince, and I finally gave up.
Repair welding of high chrome iron parts is a big NO NO. I would suggest replacing it fast. As a stop-gap, recently for 2 dredger pump castings , I offered Hardox 500. This gave them some breathing time and keep the machines working.
The replacement by Hardox 500 does not include impeller or...
" Rubbing sheet" never came across this term,in my long metal casting career. The pictures do not speak great about any surface finish requirements.
Samples remind me of high Manganese steel castings. Sorry cannot make any sense.
I had the opportunity to visit bearing manufacturers for their heat resistant steel parts and accessories.It was always through hardening for automobile and general engineering purposes.
ArkadiuszP,
I use a tungsten carbide insert of a similar dimensions as described by you.These are fixed on inlet and exit ports of a horizontal shaft impactor machine for crushing quartz .
I mill a slot and applying a quick fix glue tap the carbide insert into the slot. No brazing is done and...
Thanks for the correction. Total residual elements still remain 1% , and no mention is made of Al content. Though, I have a research publication recommending to ASTM a maximum Al content of 0.08%.
Like bobjustbob mentioned ,, 216 grade carbon steel casting is commonly specified. There is upper limit on Al content,to prevent rock candy type of fracrture. Similarly all trace elements together must not exceed 0.5%.
I am comfortable using portable brinell or the Poldi test. The reference test bars must be from a standard company, else can get erroneous results.
Rebound hardness testers are accurate on test blocks and not on the casting surfaces .
