Suppose that you have an ASTM standard round tensile specimen of SAE4340 steel w

Question

Suppose that you have an ASTM standard round tensile specimen of SAE4340 steel with the following gauge dimensions: gauge diameter 12.5 mm, gauge length -50 mm. You are to strairn Tensile properties of SAE4340 steel are listed in the Table Q4. Is it safe for you to use this machine for your specimen? Support your answer with detailed calculations. Table Q4. Tensile Properties of 4340 Steel Quenched and Tempered at 540°C Property Elastic Modulus (GPa) Yield Strength (MPa) Ultimate Tensile Strength (MPa) Elongation in 50 mm (%) Value 205 1160 1240 17

Explanation / Answer

Given data for specimen:

Yield stress= 1160Mpa = 1160 N/mm2

UTS= 1240Mpa = 1240 N/mm2

specimen dia = 12.5 mm (gauge dia)

Given data for machine:

Load capacity = 145 KN = 145000 N

Solution:

The dia of specimen is given as 12.5mm, so the area of Cross section will be 122.65mm2.

The maximum loading capacity of the machine is given as 145000N.

Therefore the maximum stress induced in the specimen will be 145000/122.65 = 1182.22 N/mm2.

This shows that the specimen cannot be tested in this machine because, the ultimate stress is the specimen is more than the capacity of the machine.

Hence this machine is NOT suitable to test this specimen. Higher capacity machines with more than 200KN capacity has to be chosen.

Related Questions

Navigate

• Browse (All)
• Browse S
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.