A kind of cast iron material and its production process

Abstract

The invention discloses an iron casting material. The iron casting material is prepared from, by mass, 60-80 parts of foundry return, 20-30 parts of waste steel and 10-30 parts of pig iron. The iron casting material includes, by mass percent, 2.9-3.2% of C, 3.5-4.2% of Si, smaller than or equal to 0.15% of Mn, smaller than or equal to 0.025% of P, smaller than or equal to 0.015% of S, smaller than or equal to 0.025% of Ti, smaller than and equal to 0.02-0.05% of other impurities and the balance Fe. The high-purity pig iron, the waste steel and the foundry returns are used as the raw materials, the total content of microelements in furnace burdens is better controlled, various kinds of interference during solidification is avoided due to the reduction of the total content of the microelements, the Mn content is reduced, and the Ti content is greatly reduced; in addition, due to a machining nodulizing agent, the nodularity in the iron casting material reaches the second level or higher, generation of pearlite is reduced due to sufficient solidification of Si, and the content of ferrite reaches 93% or so; and furthermore, due to solidification of Si, the strength of the iron casting material reaches 580-650 MPa, ductility reaches 21%-25%, surface hardness reaches 180-200 HB, high ductility and low surface hardness are ensured, hardness of a casting is distributed evenly, and the casting is convenient to machine.

Description

technical field

[0001] The invention relates to the technical field of metal smelting, in particular to an iron casting material and a production process thereof. Background technique

[0002] Ductile cast iron is treated with spheroidization and inoculation, and the graphite form is spherical cast iron, which effectively improves the mechanical properties of cast iron, especially the plasticity and toughness, so as to obtain higher strength than carbon steel. According to different shapes, nodular cast iron The inclusion in: 1. Ferrite has a body-centered cubic lattice, which is an interstitial solid solution of carbon dissolved in α-Fe, which is called ferrite, that is, α-Fe and the solid solution based on it, represented by the symbol F; 2. Pearlite is a eutectoid of ferrite and cementite formed by eutectoid transformation of austenite. Its form is a layered complex phase in which ferrite thin layers and cementite thin layers alternately overlap, also known as lamellar p...

Examples

Embodiment 1

[0026] Embodiment 1: an iron casting material, including 65 parts by mass of returned material, 23 parts of scrap steel, and 15 parts of pig iron; the mass components of the iron casting material include: C: 2.9%, Si: 3.5%, Mn≤0.15%, P≤0.025%, S≤0.015%, Ti≤0.025%, the total content of other impurities≤0.02%, and the balance is Fe.

[0027] Pearlite and ferrite in the material of the iron casting account for 5% and 95% respectively.

[0028] Its production process comprises the following steps:

[0029] (a) Furnace charge selection: High-purity pig iron, low-Mn, low-P, low-S scrap steel and recycled materials are used as furnace materials; pig iron, recycled materials and scrap steel are added to the melting furnace in sequence.

[0030] (b) Smelting: The raw molten iron is smelted in an intermediate frequency induction furnace, and the furnace temperature is 1540°C;

[0031] (c) ZFCR-6 is selected as the nodulizer, the addition amount is 0.9%, and 75Si-Fe and Si-Ba are used as...

Embodiment 2

[0037] Embodiment 2: A kind of iron casting material, including 67 parts by mass of returned material, 25 parts of scrap steel, and 23 parts of pig iron; the quality components of the iron casting material include: C: 3.0%, Si: 3.7%, Mn≤0.10%, P≤0.015%, S≤0.005%, Ti≤0.005%, the total content of other impurities≤0.015%, and the balance is Fe.

[0038] Pearlite and ferrite in the cast iron material account for 7% and 93% respectively.

[0039] Its production process comprises the following steps:

[0040] (a) Furnace charge selection: High-purity pig iron, low-Mn, low-P, low-S scrap steel and recycled materials are used as furnace materials; pig iron, recycled materials and scrap steel are added to the melting furnace in sequence.

[0041] (b) Smelting: The raw molten iron is smelted in an intermediate frequency induction furnace, and the furnace temperature is 1546°C;

[0042] (c) ZFCR-6 is selected as the nodulizer, the addition amount is 0.93%, and 75Si-Fe and Si-Ba are sel...

Embodiment 3

[0048] Embodiment 3: A kind of iron casting material, including 60 parts by mass of returned materials, 20 parts of scrap steel, and 10 parts of pig iron; the mass components of the iron casting material include: C: 3.03%, Si: 3.78%, Mn≤0.10%, P≤0.015%, S≤0.005%, Ti≤0.005%, the total content of other impurities≤0.015%, and the balance is Fe.

[0049] Pearlite and ferrite in the cast iron material account for 6.5% and 93.5% respectively.

[0050] Its production process comprises the following steps:

[0051] (a) Furnace charge selection: High-purity pig iron, low-Mn, low-P, low-S scrap steel and recycled materials are used as furnace materials; pig iron, recycled materials and scrap steel are added to the melting furnace in sequence.

[0052] (b) Smelting: The raw molten iron is smelted in an intermediate frequency induction furnace, and the furnace temperature is 1543°C;

[0053] (c) ZFCR-6 is selected as the nodulizer, the addition amount is 0.99%, and 75Si-Fe and Si-Ba are...

technical field

[0001] The invention relates to the technical field of metal smelting, in particular to an iron casting material and a production process thereof. Background technique

[0002] Ductile cast iron is treated with spheroidization and inoculation, and the graphite form is spherical cast iron, which effectively improves the mechanical properties of cast iron, especially the plasticity and toughness, so as to obtain higher strength than carbon steel. According to different shapes, nodular cast iron The inclusion in: 1. Ferrite has a body-centered cubic lattice, which is an interstitial solid solution of carbon dissolved in α-Fe, which is called ferrite, that is, α-Fe and the solid solution based on it, represented by the symbol F; 2. Pearlite is a eutectoid of ferrite and cementite formed by eutectoid transformation of austenite. Its form is a layered complex phase in which ferrite thin layers and cementite thin layers alternately overlap, also known as lamellar p...

Examples

Embodiment 1

[0026] Embodiment 1: an iron casting material, including 65 parts by mass of returned material, 23 parts of scrap steel, and 15 parts of pig iron; the mass components of the iron casting material include: C: 2.9%, Si: 3.5%, Mn≤0.15%, P≤0.025%, S≤0.015%, Ti≤0.025%, the total content of other impurities≤0.02%, and the balance is Fe.

[0027] Pearlite and ferrite in the material of the iron casting account for 5% and 95% respectively.

[0028] Its production process comprises the following steps:

[0029] (a) Furnace charge selection: High-purity pig iron, low-Mn, low-P, low-S scrap steel and recycled materials are used as furnace materials; pig iron, recycled materials and scrap steel are added to the melting furnace in sequence.

[0030] (b) Smelting: The raw molten iron is smelted in an intermediate frequency induction furnace, and the furnace temperature is 1540°C;

[0031] (c) ZFCR-6 is selected as the nodulizer, the addition amount is 0.9%, and 75Si-Fe and Si-Ba are used as...

Embodiment 2

[0037] Embodiment 2: A kind of iron casting material, including 67 parts by mass of returned material, 25 parts of scrap steel, and 23 parts of pig iron; the quality components of the iron casting material include: C: 3.0%, Si: 3.7%, Mn≤0.10%, P≤0.015%, S≤0.005%, Ti≤0.005%, the total content of other impurities≤0.015%, and the balance is Fe.

[0038] Pearlite and ferrite in the cast iron material account for 7% and 93% respectively.

[0039] Its production process comprises the following steps:

[0040] (a) Furnace charge selection: High-purity pig iron, low-Mn, low-P, low-S scrap steel and recycled materials are used as furnace materials; pig iron, recycled materials and scrap steel are added to the melting furnace in sequence.

[0041] (b) Smelting: The raw molten iron is smelted in an intermediate frequency induction furnace, and the furnace temperature is 1546°C;

[0042] (c) ZFCR-6 is selected as the nodulizer, the addition amount is 0.93%, and 75Si-Fe and Si-Ba are sel...

Embodiment 3

[0048] Embodiment 3: A kind of iron casting material, including 60 parts by mass of returned materials, 20 parts of scrap steel, and 10 parts of pig iron; the mass components of the iron casting material include: C: 3.03%, Si: 3.78%, Mn≤0.10%, P≤0.015%, S≤0.005%, Ti≤0.005%, the total content of other impurities≤0.015%, and the balance is Fe.

[0049] Pearlite and ferrite in the cast iron material account for 6.5% and 93.5% respectively.

[0050] Its production process comprises the following steps:

[0051] (a) Furnace charge selection: High-purity pig iron, low-Mn, low-P, low-S scrap steel and recycled materials are used as furnace materials; pig iron, recycled materials and scrap steel are added to the melting furnace in sequence.

[0052] (b) Smelting: The raw molten iron is smelted in an intermediate frequency induction furnace, and the furnace temperature is 1543°C;

[0053] (c) ZFCR-6 is selected as the nodulizer, the addition amount is 0.99%, and 75Si-Fe and Si-Ba are...