It is basically a study conducted on line pipe steel to determine its physical, mechanical and chemical properties for specific purpose in pipeline industry.

1. SUBMITTED BY
RAJESH KAR
(BIT SINDRI)

2.  Introduction
 Litrature review
 Experimental analysis
 Results and discussion
 Conclusion
 Reference

3.  The aim of this project is to present the underlying
characterstic of physical, mechanical properties of line
pipe steel (API X70).
 They are produced by stretching the steel out into
seamless tube or forcing the edges together and sealing
them with a weld.
 Excellent uniformity and exceptional formability are
needed to produce steel pipes of this quality.

4.  Basic concept of line pipe steel
Pipelines are efficient means of mass transportation of fluids
over long distance. Primarily they were designed for
transportation of basic energy sources like oil and gas over
the years.
 Property requirement of line pipe steel
The most popular document specifying the line pipe material
is the API that specifies the steel grades with a range of
properties. Mainly these properties depend on chemical
composition and microstructure.

7.  Chemical analysis:
First of all, cutting the sample from API X70 in dimensions of
30mm*30mm.Then paper grinding is done for polishing and
cleaning the surface of the sample before loading in optical
emission spectrometer.
 Microstructural analysis:
First the sample is cut into dimension 10mm*10mm from the
sheet in both the direction-rolling as well as transverse.The
sample is then polished with emery paper of grade 180, 320,
600, 800 and 1200 in increasing order.

8.  Tensile specimen:
Gauge length-50 mm Radius of fillet-13mm
Length of grip-50 mm Length of reduced sec-60 mm
Width of gauge-12.5 mm

9.  Specimen dimensions:
Length -55 mm Width-10 mm
Height-10 mm Angle of notch-45 degree
Finish requirement-2 micron

10.  Chemical analysis result

13.  It is concluded that API X70 is a value added
product of high importance with close control over
mechanical properties.
 The microstructure of this grade shows ferrite and
pearlite structure.
 Yield strength of this grade is of the order of 540
mpa and UTS in the range of 585 mpa.
 Both toughness and yield strength can be increased
by adding micro alloying elements.

14.  API specification 5L, “Specification of line pipe” 42nd Edition, 2000,
American Petroleum Institute, USA.
 Kalwa, G., Kaup, “Steels for Linepipe”, Steel A Handbook for Material
Research and engineering, Volume 2, Springer-Verlag Verlag Staheisen
mbH.
 Orton, J.P.,”An overview of Line Pipe ”, Microalloying 75, Conference
Proceedings.
 B. L. Jones, “Pipeline Steel for Sour Gas Transport”, Technical Report,
Niobium Products Company, Ltd., Pittsburgh, PA, USA, 1985.
 J. Y. koo et al.,” Metallurgical Design of Ultra High – Strength Steels for
Gas Pipelines,” International Journal of Offshore and polar Engineering,
Vol. 14, 2004, 2-10.
 M. K. Graff, H. G. Hillenbrand and P. A. Peters,”Accelerated Cooling of
Plate for High Strength Large Diameter Pipe”, Accelerated Cooling of
Steel, TMS-AIME, Warrendale, PA, USA, 1986.