Recent content by lidbasky

@Dear MagBen Thanks for comments. As said before when I check it by magnet it is semi magnetic so it has other phase than austenite. We do a lot of machining from centrifugsl casting cylinder to final ring. What is your idea about defects in attached picture what is the cause of this defects...

Thanks Ed for useful informations. It is a gas turbine part to make stable clearance during working. It is used in cold section of turbine and up to 350 c. So specially designed by gas turbine manufacturer. As a conclusion the indications that revealed in PT test after machining (see attached...

EdStainless Really I don't know this is a Kovar or Super Invar. I am working on this alloy for a long time. But it is a castable very low CTE alloy up to 350 C. I don't know why designer used such huge amount of Carbon. I have checked before Co-Fe-Ni phase diagram and it is shown the region that...

Deararunmrao I should explain more. Due to presence of Cobalt and also high amount of Carbon in this alloy (0.45 to 0.55 %) it is not fully austenitic and as I check in the phase diagram it is dual phase (austenite+ferrite)and maybe high amount of carbides. On the other hand the amazing thing...

Dear Arunmrao It is centrifugal casting cylinder. There is no feeder. We cut rings from cylinder and machined them. The image shows ring after cutting and machining. I think it is hot tear due to excess centrifugal force than shrinkage defects. But casting supplier says that maybe they are...

Dear EdStainless Thanks. It is stress relieved. It is inside of ring. More than 5 mm was removed. You can see PT result in attachment.https://files.engineering.com/getfile.aspx?folder=3dff36fe-45ef-4dd7-b66d-1efb8e86f538&file=20200108_163334.jpg

Does anybody had experience with machining of castable super invar. I am working on centrifugal castin ring. Material is special super invar containing 28Ni-14Co-0.5C. After machinig and PT I saw some crack like indications. Is it possible that cracks occure due to bad machining? Does super...

Dear Ed In the requirements of part was written that average grain size shall be max No. 8 and occasional grains shall be max No. 7 according to ASTM E112. Shall I report the biggest grain which I observed in 3 or 5 microstructure images?

Hi, What is the meaning of occasional grain ? How can I measure size of occasional grains and how shall I report it (max occasional grain)? Is there any standard for determining occasional grains in metals? I need to determine average grain size and max occasional grains in IN718 forging part...

i check inco, i cant find In 3501,but i found Nilo k alloy which is an Fe-Ni-Co alloy, and has low thermal expansion. but my alloy has so many alloying elemnts which make production of it difficult. could anyone help me or give me some information about these alloys?

No, i dont do that. i googled for a long time but i didnt find anything.

I think it is because of that cast Ni base superalloys could have more volume fraction of gamma prime phase than wrought superalloys, which make cast one stronger.

Did anybody heard something about alloy inconel 3501. A special Fe-Ni-Co alloy with low coefficient of thermal expansion?

I should mention that The sample is cast separately as a Y block or Kill block. The size of Y block is related to relevant thickness of casting. In standard there is table for choosing test block dimension regarding to casting relevant thickness.

Thank you arunmrao, but I am the customer of part and in the drawing of the casting, there is no guide for relevant wall thickness. Are you sure that it is the thick section of castings?