LSAW Steel Pipe
X60 is a steel grade specified by the American Petroleum Institute Standard (APL). Its chemical composition: C is less than or equal to 0.28, and MN is less than or equal to 1.40. The first grade yield strength (MPA) is greater than or equal to 4isposition: degree (MPA) is greater than or equal to 547.
2, the mechanical properties of steel is an important indicator to ensure the final performance of the steel (mechanical properties), it depends on the chemical composition of the steel and heat treatment system. In the steel pipe standard, tensile properties (tensile strength, yield strength or yield point, elongation), hardness and toughness indexes, and high and low temperature properties required by users are specified according to different use requirements.
1 tensile strength (σb)
The maximum force (Fb) that the specimen is subjected to during the drawing process, divided by the original cross-sectional area (So) of the specimen, is called the tensile strength (σb). The unit is N/mm2 (MPa). It represents the maximum ability of a metal material to resist damage under tensile forces. The calculation formula is:
Where: Fb--the maximum force to be taken when the sample is broken, N (Newton); So--the original cross-sectional area of the sample, mm2.
2 yield point (σs)
The metal material with yielding phenomenon, the force of the sample does not increase (maintains constant) during the stretching process, and the stress at the time of elongation can be continued, which is called the yield point. If the force drops, the upper and lower yield points should be distinguished. The unit of yield point is N/mm2 (MPa).
Upper yield point (σsu): the maximum stress before the specimen yields and the first drop of force; the lower yield point (σsl): the minimum stress in the yielding phase when the initial transient effect is not counted.