US 5,288,346 AGranted

Process for producing deformable white cast iron

AssigneeDmk Tek, Inc.

InventorsPolina F. Nizhnikovskaja, Leonid Snagovski, Yuri Taran, Tatyana Mironova, Michael Loiferman, Kasimir Zhdanovich, Galina Demchenko

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Abstract

A process for deforming white cast iron. A melt is prepared containing iron, carbon and one or more alloying elements. The melt is cooled at a rate of approximately 2.degree. C. per minute or faster to form a white cast iron material. The white cast iron material is annealed at a temperature of about 100.degree. C. to about 400.degree. C. below the solidus temperature of the white cast iron material. The white cast iron is plastically deformed.

Claims8

Dependent claims

A process for plastically deforming a white cast-iron, said process comprising the steps of:

(a) preparing a melt consisting essentially of:
(i) about 2.0 to about 3.7 percent by weight of carbon;
(ii) vanadium in an amount of about 1.5 to about 1.9 percent by weight;
and
(iii) the balance iron;
(b) cooling said melt at a rate of at least about 30.degree. C. per minute for forming a white cast-iron material having a structure including a metastable cementite phase;
(c) annealing said white cast-iron material at a temperature of about 100.degree. C. to about 400.degree. C. below its solidus temperature for transforming said metastable cementite phase and forming a structure including Fe.sub.3 C and vanadium carbide, said vanadium carbide being more stable than said metastable carbide;
wherein the amount of said metastable cementite phase that is transformed is sufficient to permit plastic deformation of said white cast iron at a temperature as low as about 850.degree. C., and at a deformation rate ranging from about 1/sec to about 10/sec;
and
(d) then plastically deforming said white cast-iron material at a temperature as low as about 850.degree. C., and at a deformation rate ranging from about 1/sec to about 10/sec.

7 more elements

A process for plastically deforming a white cast-iron, said process comprising the steps of:

(a) preparing a melt consisting essentially of:
(i) about 2.0 to about 3.7% by weight of carbon;
(ii) at least one carbide-forming element selected from the group consisting of manganese, chromium, molybdenum, tungsten, vanadium, titanium, niobium, tantalum, zirconium, hafnium, uranium and mixtures thereof, wherein the amount of said carbide-forming element is selected in accordance with the formula:
E.sub.1 +1.49 E.sub.2 +3.03 E.sub.3 +5.88 E.sub.4 +76.9 E.sub.5 =(about 1.51 to about 3.27) E.sub.6 ;
wherein:
E.sub.1 is the concentration of elements selected from the group consisting of manganese, chromium and mixtures thereof;
E.sub.2 is the concentration of elements selected from the group consisting of tungsten, molybdenum, and mixtures thereof;
E.sub.3 is the concentration of elements selected from the group consisting of vanadium, titanium and mixtures thereof;
E.sub.4 is the concentration of elements selected from the group consisting of niobium, tantalum, and mixtures thereof;
E.sub.5 is the concentration of elements selected from the group consisting of hafnium, uranium, and mixtures thereof;
and
E.sub.6 is the concentration of carbon;
and
(iii) the balance iron;
(b) cooling said melt at a rate of at least about 2.degree. C. per minute for forming a white cast-iron material having a structure with a metastable cementite (M.sub.3 C) phase;
(c) annealing said white cast-iron material at a temperature of about 100.degree. C. to about 400.degree. C. below the solidus temperature of said white cast-iron material for transforming said metastable cementite phase and forming a structure containing Fe.sub.3 C, and a carbide denoted as M'C where M' is at least one of said carbide-forming elements, wherein said M'C is a more stable carbide than said M.sub.3 C, wherein the presence of said M'C facilitates plastic deformation of said white cast iron;
and further wherein the amount of said metastable cementite phase that is transformed is sufficient to permit plastic deformation of said white cast iron at a temperature as low as about 850.degree. C., and at a deformation rate ranging from about 1/sec to about 10/sec;
and
(d) then plastically deforming said white cast iron material having said M'C at a temperature as low as about 850.degree. C., and at a deformation rate ranging from about 1/sec to about 10/sec.

16 more elements

Dependencies are inferred from the claim text.

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Abstract