Evaluating Odd Steel Types

[Boiler8019]

Interesting question came up today. Have a 3" diameter solid dowel pin connecting two elements that have 200 kip axial load in them. The fabricator is asking wether or not steel A4150 is acceptable. Has anyone ever heard of this stuff and/or run into a similar situation? How do you evaluate steels that we typically dont use every day?

 

[csd72]

You need to find out what the appropriate ASTM standard is for that material.

 

[miecz]

According to my old Ryerson Stock list and Data Book, AISI 4150 is a Commercial Quality Alloy Steel available in round and flat stock. Apparently, it can be quenched and tempered.

The hot rolled properties were listed as:
Tensile Strength: 100 ksi
Yield Strength: 66 ksi
% Elongation (2"): 21
% Reduction of area: 51
Hardness BR. 197
Hardness R: B93

The quenched and tempered properties were listed as:
Tensile Strength: 158 ksi
Yield Strength: 134 ksi
% Elongation (2"): 14
% Reduction of area: 42
Hardness BR. 311
Hardness R: C33

 

[Boiler8019]

Thanks for that AISI info. How would one interpret this to make sure its not a brittle material that will crack under numorous stress reversals?

 

[plasgears]

It looks like you need to design a test article that duplicates geometry and applied loads and other operating conditions.

 

[miecz]

Don't know for sure. I guess you need to talk to a materials expert. I'd call a local supplier or look for a materials forum under mechanical engineering. If fatigue is your concern, I believe it's the % elongation figure that's a measure of brittleness, and the numbers above are in the middle range of most steels. I wouldn't worry unless you have a stress concentration, such as a slot or hole or threads.