4130/4140 mechanical proporties

[581127]

i am trying to do a failure analysis for the impeller made of AISI4130/4140(forging), but i don't know the proporties in the standard specification ,anyone can help me? thanks.

 

[kclim]

4140 has higher carbon (0.40 %, last two digits denote nominal C content) than 4130 (0.30%), and consequently has higher hardness and hardenability.

You should be able to find some standard properties on matweb (

http://www.matweb.com).

Google searches will also turn up quite a bit of information.

Good luck

 

[metengr]

The mechanical properties of the impeller material would most likely be specified by the original equipment manufacturer of the pump. This information may be difficult to obtain.

Are you sure the impeller is a forging and not a casting? Most pump impellers are typically cast products.

What type of failure did you have, and what is the pump?

 

[581127]

thanks for the help. as metengr said it's different to find the mechanical properties of the impeller material (for the compressor not for the pump),but i want to know the Minimum Tensile Properties that AISI4130/4140 standard specification specified, how can i find it ?

 

[Carburize]

581127 - there is no "standard specification" for the mechanical properties of these two alloys. Both are used extensively in many applications and heat treat treated to various strength levels. A "typical" minimum tensile strength would be 90,000 psi but ultimate strengths up to 170,000 are achievable.

 

[581127]

i have just found a webpage(

http://www.qualityforgings.co.uk/spec_4130-80.htm)

in which there are some proporties data such as "HEAT TREATED AND TESTED TO:
Tensile - 100,000 PSI (690 N/mm2),Yield - 80,000 PSI (552 Nmm2),Elongation in 2"L - 18%, Reduction of Area - 35%",if i can consider these date are the Minimum Tensile Properties?

 

[Carburize]

581127 - as I indicated in an earlier reply the UTS could be lower but the values you quote are a reasonable estimate of the likely minimum properties.When doing your failure analysis, be careful however, not to place too much emphasis on this data, you really need to know the strength level specified by the original designer/manufacturer in order to properly evaluate any problem concerning strength.