suggestion for casting standard 3

[forensiclab]

I have an extruding machine which has fractured. It is made of grey cast iron. The fractures reveal obvious defects and the surface is very poor. Could someone suggest a standard from USA, UK or Australia that I could refer to so as to judge the condition of the casting?

 

[TVP]

These 3 standards would be a good place to begin:

ASTM ASTM E 94 Standard Guide for Radiographic Examination

ASTM E 1030 Test Method for Radiographic Examination of Metallic Castings

ASTM E 689 Reference Radiographs for Ductile Iron Castings

 

[Flesh]

A metallurigical analysis will also be important for your failure analysis:

ASTM E48 Standard Specification for Gray Iron Castings

SAE J431 Automotive Gray Iron Castings (Even though the title states "automotive", this spec will give you some insight as to what makes a good casting: microstructure, graphite flake type, and mechanical properties.)

 

[MOB1]

You do not mention how thick the casting is.
Radiographic techniques to check the inetrnal integrity have thickness limitations. Ultrasonics also are limited in their ability to detect internal casting defects in gray cast iron.
I would agree with Flesh that you should have a metallurgical analysis of the fracture carried out and a company which does this work should be able to offer advice on quality standards and inspection methods.

 

[unclesyd]

If the defects are as bad as you state there are not many standards or inspection techniques that are of any value. When a casting is extremely bad, as yours, you best bet is to get the machine manufacturer involved very quickly.

Do mess with the failure surfaces in any way.

You just have to document the failure, photographs by a competent or professional photographer, and point the defects out to the manufacturer and await his comments. Sometime this is hard to do unless someone is hurt or said failure has a potential to hurt someone. The problems come if there is no response from the manufacturer.

I have been involved in several such cases where it turned in to a legal thing very quickly. In every case the owner of the machine received judgement though not as much as I thought was reasonable in most cases.