Specification :

BEND 22, 5 DEGREE SOCKET MECHANICAL JOINT.
FOR JOINER PIPE.
Nodular cast iron or ductile cast iron is an alloy of iron with carbon around 3% . In addition to other carbon base alloys are Si, Mn and Mg. The highest class of normal ductile iron has a maximum strength of 800 MPa. Microstructure of ductile iron in general is a nodular graphite matrix pearlitic or pearlitic-ferritic. Development of ductile iron for increased strength to above 1000 MPa can be done by forming the basic matrix of a bainitic ductile iron.

Bainitic matrix can be achieved through a process of austempering heat treatment. In addition there are other, more economical method is by adding a special alloy of nickel and molybdenum. Integration method in liquid nickel-molybdem nodular cast iron will produce as-cast bainitic matrix that is direct so long as the process of freezing and cooling in a sand mold without heat treatment. Another thing that also affect the chemical composition is other than cooling rate.

For objects with different cooling rates should be adjusted so that the alloy composition can produce as-cast bainitic matrix are more homogeneous. The main function of nickel-molybdenum alloy is to shift the pearlite nose of CCT diagram of ductile iron to be backward and forward over the next bainite nose. With the current economic conditions, the normal cooling rate of bainite matrix will be obtained.