Our pipe has been past through ISO9001 Quality Insurance System Certificate , Carrying our 2531\4179\8179\EN545, GB\T13295\17459\17457\17456 standard strictly to assure the product quality all through the manufacture process. Ductile cast iron is a kind of alloy of iron , carbon and silicon , in which graphite exists in the type of spherical, generally the size of graphite is 7~7 class, and spheriodization grade of the pipe should be controlled 1~3 class (spheroidization rate is not below80% ) . Thus after spheroidization, ductile cast iron possesses the nature of iron as well as the characteristics of steel. After annealing, its microstructure contains ferrite and a little pearlite possessing excellent mechanical properties. Mechanical properties: ST (Tensile Strength) : >= 420MPa Yield Strength (YS) : >= 300MPaBending Strength: >= 590MPa Elongation: >= 10% Chemical Composition: C 3. 5- 4. 0% Si 1. 9- 2. 6% Mn 0. 15- 0. 45% P <= 0. 06% S <= 0. 02% Mg 0. 03- 0. 06
