ASTM E21 Test for Elevated Temperature Tension Tests of Metallic Materials

Specimen size:

Usually, a tensile specimen has two shoulders and a gauge section between them. The shoulders are bigger so they can be easily gripped and the gauge section has a smaller cross-section so that deformation and failure can occur in this area. 

• The size and shape of the test specimens used in ASTM E21 testing should be based primarily on the requirements necessary to obtain representative samples of the material being investigated.
• Specimens with circular cross-sections should have gripping ends that are threaded or shouldered. 
• The width at the ends of the reduced section should not be less than the width at the center of the reduced section. 

Data:

The following data is calculated in ASTM E21:

1. Tensile strength:

S_u = P_max  /A

S_u  = the tensile strength

P_max = the maximum load

2. Yield point:

the stress beyond which a material becomes plastic,

 YP  = P_YP /A₀
 P_YP = load at the yield point.

3. Percentage elongation:

The extent to which the test specimen has stretched at failure,

Elongation = ɛ = (ΔL/L₀) x 100

 ΔL: Change in length

 L₀: Initial length

4. The percentage reduction of area (%RA):

The amount the specimen has necked or reduced in diameter at the point of failure 

Conclusion:

ASTM E21 covers elevated temperature tension testing of metals. It is used to determine the ability of metals to withstand tensile forces at higher temperatures.