Spheroidizing pearlite and production method thereof

Abstract

The invention relates to a nodulizing pearlite and a production method thereof and relates to the technical field of metallurgical technique. The production method comprises the following steps: 10 to 91.7 percent of scrap steel, 0 to 53.3 percent of scrap returns, 0 to 75 percent of pig iron, 0 to 3.87 percent of recarburizing agent, 0 to 1.53 percent of ferrosilicon and 0.2 to 0.67 percent of ferromanganese are thrown into a medium frequency induction furnace with acid lining; after being molten, the obtained mixture is poured in a ladle with 1.4 to 1.6 percent of rare earth ferrosilicomagnesium alloy and part of inoculant; then the remaining inoculant is added again; and the pearlite QT700-2 is formed after spheroidization. The invention does not use pig iron or uses little pig iron, but uses large amount of scrap steel and scrap returns so as to save the cost of raw materials; synthetic cast iron using a recarburizing method for adjusting the carbon content and a smelting method thereof contain 3.7 to 3.9 percent of C, precipitates large amount of graphite, have small dimension of sphere diameter, increase roundness and can reduce the hole area and reduce the area of shrinkage porosity, thus leading the casting product to be more compact.

Description

Technical field [0001] The invention relates to the technical field of metallurgical technology, in particular to the technical field of the production of pearlite for metal parts. Background technique [0002] The metal charge of molten iron is generally composed of new iron, scrap steel, reheat charge and ferroalloy. The current production of pearlite QT700-2 mostly uses about 65% of nascent iron, 5% of scrap steel, in addition to 0.3% of Mo and 0.6% of copper. Due to the high price of nascent iron, the product price remains high. And the product has the following defects: the phenomenon of inverted white holes in the castings makes machining difficult, and the processing tools are worn. In addition, shrinkage tends to occur in the part where the phenomenon of inverted mouth occurs, and the basic structure contains more carbides, which leads to a decrease in the mechanical properties of the part. Summary of the invention [0003] The purpose of the present invention is to inve...

AI Technical Summary

Problems solved by technology

And the product has the following defects: the phenomenon of anti-whitening of the casting makes machining difficult, and the machining tool is worn

In addition, in the part where the anti-whitening phenomenon occurs, shrinkage often occurs, and the basic structure contains more carbides, which leads to a decrease in the mechanical properties of the part