How to check the quality of iron castings?
(Part 2)

In the previous article, we have talked about some main aspects of inspecting iron castings, such as dimensions, tensile strength, hardness, surface and inside defects, herein, we continue to talk about some other aspects including how to check yield strength, elongation, chemical components, compact property.

Yield Strength

Although many people know yield strength, but it usually did not be required by designers and buyers, except of special application. The yield strength is usually calculated by the test result of multi-functional test machine.

Elongation

Elongation is showing the stretch properties of iron castings. Which is also tested by the multi-functional test machine. Most of foundries in China could test it, and it is an important physical property. When you require the 60-40-18 or 65-45-12 ductile iron, then the 18 and 12 will be the elongation. It is a percent parameter, such as 18% and 12%. Larger will be better.

Chemical Components

Many clients required the chemical components to control the materials. Usually, buyers and designers just need to stipulate the material grade / degree such as ASTM A536 CLASS 60-40-18, then the foundries will know the standard chemical components and physical properties. So, you do not need to stipulate the chemical components, expect you really need to stipulate it in order to meet other special requirement of application. For example, if you want to increase the wear-resistant, you could require to add some Cu. If you want to increase the heat-resistant, you could require to add some Cr. Please do not make your chemical components conflictive with your material degree. If you do, the foundries will not understand what standard they should take.

Compact Property

Some clients will require the V-Compact test for their iron castings. Charpy impact test method for metallic materials is specified by European EN 10045 standard. This specification defines terms, dimension and tolerances of test pieces, type of the notch (U or V), test force, verification of impact testing machines etc.

If your final clients or designers really required this compact test, then you will have to do it. There are some metallic material laboratories in Shenyang and Beijing, such as National Analysis Center for Iron and Steel. They can do this test for you or for your suppliers. So, you could ask your suppliers to make the test specimen, and send them to these laboratories, then they will issue the English reports to you.

As for the buyers, please denote the test temperature for the compact test. The test temperature is very important for this kind of test.

In the future, we will take more about surface smoothness, surface coating, packing requirement, FOB and CIF delivery, various payment terms and international trading risks etc. Please check the updated articles in Dandong Foundry.

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