Method for increasing creep rate of compacted graphite cast iron by electromagnetic field

Abstract

The invention relates to a production method of vermicular graphite cast iron, in particular to a method for improving the vermicular rate of vermicular graphite cast iron by using a pulsed electromagnetic field. First, add vermative agent and inoculant to the molten iron, perform vermicular treatment at a temperature of 1420-1450°C, and then pour the treated molten iron into the experimental mold, the main point of which is to apply intermittent commutation to the pouring mold Traveling wave magnetic field, the power frequency is 50 Hz, and the magnetic induction is 0.01-0.03T. Finally, vermicular graphite cast iron with a creep rate of more than 75% can be obtained, and the residual content of magnesium and rare earth can reach Mg respectively. 残 =0.01~0.05%, Re 残 = 0.01 to 0.03%. The technical breakthrough of the invention opens up a new way for the production of vermicular graphite cast iron.

Description

Technical field [0001] The invention belongs to a production method of vermicular graphite cast iron, in particular to a production method of improving the vermicular rate and creep stability of vermicular graphite cast iron by using an electromagnetic field. Background technique [0002] The good mechanical properties, thermal stability and good casting performance of compacted graphite cast iron have attracted widespread attention, and have been widely used in the manufacture of automobile engine blocks, cylinder heads, exhaust pipes, brake hubs, steel ingot molds and glass molds. [0003] At present, the key problem in the production of vermicular cast iron is that the vermicular rate is not stable, and the improvement of vermicular rate depends on the formation and stabilization of vermicular graphite in vermicular graphite cast iron. The existing production methods of vermicular graphite cast iron mainly contain three kinds: (1) process molten iron with a small amount o...

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Problems solved by technology

[0004] The purpose of the present invention is to solve the problems of low creep rate and unstable creep in existing production methods, using a pulsed electromagnetic field to increase the creep rate, and to relax the residual amount of magnesium and rare earth in vermicular graphite cast iron range, improve the stability of production, and the creep rate of the final product can reach more than 75%.

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