Nodular cast iron production considerations
PubTime：2018-01-08 Author：RuiDong
Matters needing attention
(I) strict requirements for chemical composition, the content of carbon silicon required for the original iron liquid is higher than that of gray cast iron, and the content of manganese, phosphorus and sulfur in ductile iron is reduced.
(2) the temperature of iron is higher than that of gray cast iron, so as to compensate the spheroidization and the loss of iron liquid temperature during pregnancy.
(3) the spheroidization process is carried out to add the spheroidizer to the iron solution.
(4) inoculation of inoculation with inoculation.
(5) ductile iron has a poor fluidity, so it needs higher pouring temperature and larger pouring system size, reasonable application of the riser, cold iron, and the principle of sequence solidification.
(6) heat treatment.
(1) annealing.The matrix of ferrite is obtained, which improves the plasticity, toughness and stress, and improves the cutting performance.
(2) is fire.The matrix of pearlite is obtained and the strength and wear resistance are improved.
(3) conditioning.To obtain the matrix of the tempering sortenite, and good comprehensive mechanical properties, such as spindle, crankshaft, connecting rod, etc.
The work is quenched.Complicated shape, and the parts of high comprehensive performance requirements for the bainite matrix organization, as well as high strength, high hardness, high toughness, such as the comprehensive mechanics performance, avoid cracking occurring during heat treatment such as main shaft, crankshaft, gear, etc.
This paper is compiled by shenyang rudong machinery co. LTD
