steel pipe mechanical properties

steel pipe mechanical properties

 

Is to ensure that the steel pipe end-use properties (mechanical properties), an important indicator, it depends on the chemical composition and heat treatment of steel pipe system. Steel pipe standards, depending on the requirements of the provisions of the tensile properties (tensile strength, yield strength or yield point elongation) and hardness, toughness, user requirements, high and low temperature performance. 12Cr1Mov alloy tube

① tensile strength (σb) <formula>

Sample in the stretching process, in the pull-off bear most strongly (Fb), a sample of the original cross-sectional area (So) of the resultant of the stress (σ), called the tensile strength (σb) in units of N/mm2 (MPa). It indicates the maximum capacity of the metal material under tension resistance to damage. Total formula is:

Where: Fb - the specimen pulled off the most affordable vigorously N (Newton); So - the original specimen cross-sectional area, mm2.

② yield point (σs)

A metallic material having a yield phenomenon, the specimen during the tensile force does not increase (kept constant) can still continue to stretch the stress, called yield point. If the force drops, should distinguish between the lower yield point. Yield point unit N/mm2 (MPa).

Upper yield point (σsu): sample occurs to yield and force maximum stress before the first drop; under the yield point (σsl): When excluding the initial transient effect, minimum stress yield stage.

The yield point formula:

Where: Fs - sample drawing process yield force (constant), N (Newton) So - the original specimen cross-sectional area, mm2.

(3) Elongation rate (σ)

In the tensile test, the sample fractured in the percentage of its increased length gauge with the original standard pitch length, known as elongation. Σ is the unit%. The formula is:

Where: L1 - sample fractured in the gauge length, mm; the L0 - sample the original gauge length mm standard.

④ section shrinkage (ψ)

In the tensile test, the sample fractured in its reduced-diameter cross-sectional area at the maximum percentage of the reduction in the amount with the original cross-sectional area, known as the section shrinkage. The ψ said unit%. Calculated as follows:

Where: S0 - the original specimen cross-sectional area, mm2; the S1 - sample fractured necking at least cross-sectional area, mm2.