阅读说明：本技术 一种抗低温冲击球墨铸铁及其生产方法 (Low-temperature impact resistant nodular cast iron and production method thereof ) 是由 徐西兵 于杰 刘元学 于 2018-08-24 设计创作，主要内容包括：本发明公开了一种抗低温冲击球墨铸铁及其生产方法,其所包括的化学组分及其重量份为：Q10生铁40～75重量份；普通低碳钢25～60重量份；球化剂1～3重量份；长效孕育剂0.2～1.5重量份；特效孕育剂0.1～1重量份。生产方法为：S1、熔炼：炉内加入生铁和废钢,熔化到1400℃取样,做碳硫快速分析调正成份；熔炼温度≥1500℃时出铁,降温扒渣,并浇三角试块；S2、球化孕育：加入球化剂、长效孕育剂、特效孕育剂,使硅钡孕育量为0.8～1.1％；出铁,并扒除渣、保温、浇三角试片,出铁温度为1530～1500℃；S3、浇注：浇注温度1460～1370℃；S4、铸件后处理。本发明制得的球墨铸铁低温下抗冲击韧性高,完全满足高寒地区铸件使用要求。(The invention discloses low-temperature impact resistant nodular cast iron and a production method thereof, wherein the low-temperature impact resistant nodular cast iron comprises the following chemical components in parts by weight: 40-75 parts by weight of Q10 pig iron; 25-60 parts of common low-carbon steel; 1-3 parts of a nodulizer; 0.2-1.5 parts by weight of long-acting inoculant; 0.1-1 part by weight of a specific inoculant. The production method comprises the following steps: s1, smelting: adding pig iron and scrap steel into the furnace, melting to 1400 ℃, sampling, and performing rapid analysis and adjustment on carbon and sulfur; tapping when the smelting temperature is more than or equal to 1500 ℃, cooling and slagging off, and pouring a triangular test block; s2, spheroidizing inoculation: adding a nodulizer, a long-acting inoculant and a special-effect inoculant to ensure that the inoculation amount of silicon and barium is 0.8-1.1%; tapping, removing slag, preserving heat, and pouring a triangular test piece, wherein the tapping temperature is 1530-1500 ℃; s3, pouring: the casting temperature is 1460-1370 ℃; and S4, casting post-treatment. The nodular cast iron prepared by the method has high impact toughness at low temperature, and completely meets the use requirements of castings in alpine regions.)

1. The low-temperature impact resistant nodular cast iron is characterized by comprising the following chemical components in parts by weight:

2. the low-temperature impact resistant nodular cast iron according to claim 1, wherein the pig iron is Q10 pig iron, and the pig iron comprises the following chemical components in parts by weight: c is more than 3.3; si is less than or equal to 0.9; mn is less than or equal to 0.15; s is less than or equal to 0.04; p is less than or equal to 0.05.

3. The low-temperature impact resistant nodular cast iron of claim 1, wherein the chemical components and the parts by weight of the chemical components contained in the ordinary low-carbon steel are respectively as follows: c is less than 0.3; si is less than or equal to 0.3; mn is less than or equal to 0.3; s is less than or equal to 0.04; p is less than or equal to 0.05.

4. The low-temperature impact resistant nodular cast iron of claim 1, wherein the nodulizer comprises the following chemical components in parts by weight:

5. the low-temperature impact resistant nodular cast iron according to claim 1, wherein the long-acting inoculant comprises the following chemical components in parts by weight:

1.4 to 2 parts by weight of Ca

1.0 to 1.6 parts by weight of Al

63-68 parts of Si.

6. The low-temperature impact resistant nodular cast iron according to claim 1, wherein the specific inoculant comprises the following chemical components in parts by weight:

7. the low-temperature impact resistant nodular cast iron of claim 1 wherein the nodulizer has a particle size of 5-25 mm.

8. The low-temperature impact resistant nodular cast iron of claim 1, wherein the grain size of the long-acting inoculant is 3-8 mm.

9. The low-temperature impact resistant nodular cast iron of claim 1, wherein the specific inoculant has a particle size of 0.1-1 mm.

10. The production method of the low-temperature impact resistant nodular cast iron is characterized by comprising the following steps:

s1, smelting: adding 40-75 parts by weight of pig iron and 20-60 parts by weight of scrap steel into the furnace, melting to 1400 ℃, sampling, and performing rapid analysis and adjustment on carbon and sulfur; tapping when the smelting temperature is more than or equal to 1500 ℃, cooling and slagging off, and pouring a triangular test block;

s2, spheroidizing inoculation: adding 1-3 parts by weight of nodulizer, 0.2-1.5 parts by weight of long-acting inoculant with the granularity of 3-8 mm and 0.1-1 part by weight of special-effect inoculant with the granularity of 0.1-1 mm to ensure that the inoculation amount of silicon and barium is 0.8-1.1%; tapping, removing slag, preserving heat, and pouring a triangular test piece, wherein the tapping temperature is 1530-1500 ℃;

s3, pouring: the pouring temperature is 1460-1370 ℃, a pouring cup must contain molten iron, the pouring cup is not stopped, the pouring is continued, when the air outlet rod begins to emit the molten iron, the pouring is carried out slowly until a ladle is fully poured, and a riser must be supplemented with the molten iron until the riser is fully discharged;

s4, casting post-treatment: and (5) keeping the temperature for 2 hours, opening the box of the original underground clip in a size larger than 4 inches, and flatly placing the opened box casting.

Technical Field

The invention relates to the technical field of casting alloy, in particular to low-temperature impact resistant nodular cast iron for alpine regions and a production method thereof.

Background

The nodular cast iron is a cast iron material with spheroidal graphite obtained by inoculation and spheroidization, has the advantages of excellent mechanical property, processability, wear resistance, shock absorption performance, lower production cost and the like, has comprehensive properties similar to steel, and is successfully used for casting parts with complex stress and higher requirements on strength, toughness and wear resistance, such as automobile parts, cast iron pipe fittings, wind power parts, machine tool parts, engine crankshafts and the like, just because of the excellent properties. However, the common nodular cast iron has the defect of poor low-temperature impact resistance, so that the common nodular cast iron is limited in application to workpieces bearing dynamic loads at low temperature. Therefore, the development of spheroidal graphite cast iron with good low-temperature impact property is very important for the development of alpine regions.

EN-GJS-400-18-LT is the European Standard EN 1563: 1997, low-temperature nodular cast iron which has good low-temperature impact resistance. Although the national GB/T1348-1988 nodular cast iron standard has a QT400-18L mark and a corresponding reference value of impact toughness at the temperature of-20 ℃, under the condition that the normal-temperature mechanical property completely meets the requirement of QT400-18 under the common production condition, the low-temperature impact resistance of QT400-18L is often far lower than that of EN-GJS-400-18-LT.

While in the german DIN 1563 (cast-nodular cast iron) standard, only the mechanical properties and the internal material structure of EN-GJS-400-18-LT (low-temperature nodular cast iron brand) low-temperature resistant nodular cast iron are described, no description is made on how to achieve the properties, and only the relation between silicon elements and carbon elements is indicated, so that the practical significance is insufficient in actual operation. And the existing literature does not have a chemical element formula of EN-GJS-400-18-LT mark in DIN 1563 (casting-nodular cast iron) standard.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides the low-temperature impact resistant nodular cast iron and the production method thereof, the metal material formula which can be realized in a standard foundry is determined in the direction of determining low silicon and high carbon in a large frame of DIN standard, and the prepared nodular cast iron has high impact resistance toughness at low temperature and completely meets the use requirement of castings in alpine regions.

In order to solve the problems in the prior art, the adopted specific technical scheme is as follows:

the low-temperature impact resistant nodular cast iron comprises the following chemical components in parts by weight:

preferably, the pig iron is Q10 pig iron, and the pig iron comprises the following chemical components in parts by weight: c is more than 3.3; si is less than or equal to 0.9; mn is less than or equal to 0.15; s is less than or equal to 0.04; p is less than or equal to 0.05.

In a further preferred scheme, the common low-carbon steel comprises the following chemical components in parts by weight: c is less than 0.3; si is less than or equal to 0.3; mn is less than or equal to 0.3; s is less than or equal to 0.04; p is less than or equal to 0.05.

In a further preferred scheme, the grain size of the nodulizer is 5-25 mm, and the nodulizer comprises the following chemical components in parts by weight:

the particle size of the long-acting inoculant is 3-8 mm, and the long-acting inoculant comprises the following chemical components in parts by weight:

1.4 to 2 parts by weight of Ca

1.0 to 1.6 parts by weight of Al

63-68 parts of Si.

The particle size of the special-effect inoculant is 0.1-1 mm, and the special-effect inoculant comprises the following chemical components in parts by weight:

the invention also provides a production method of the low-temperature impact resistant nodular cast iron, which comprises the following steps:

s1, smelting: adding 40-75 parts by weight of pig iron and 20-60 parts by weight of scrap steel into the furnace, melting to 1400 ℃, sampling, and performing rapid analysis and adjustment on carbon and sulfur; tapping when the smelting temperature is more than or equal to 1500 ℃, cooling and slagging off, and pouring a triangular test block;

s2, spheroidizing inoculation: adding 1-3 parts by weight of nodulizer, 0.2-1.5 parts by weight of long-acting inoculant with the granularity of 3-8 mm and 0.1-1 part by weight of special-effect inoculant with the granularity of 0.1-1 mm to ensure that the inoculation amount of silicon and barium is 0.8-1.1%; tapping, removing slag, preserving heat, and pouring a triangular test piece, wherein the tapping temperature is 1530-1500 ℃;

s3, pouring: the pouring temperature is 1460-1370 ℃, a pouring cup must contain molten iron, the pouring cup is not stopped, the pouring is continued, when the air outlet rod begins to emit the molten iron, the pouring is carried out slowly until a ladle is fully poured, and a riser must be supplemented with the molten iron until the riser is fully discharged;

s4, casting post-treatment: and (5) keeping the temperature for 2 hours, opening the box of the original underground clip in a size larger than 4 inches, and flatly placing the opened box casting.

By adopting the scheme, compared with the prior art, the low-temperature impact resistant nodular cast iron and the production method thereof have the technical effects that:

1. the invention defines the component formula for producing the nodular cast iron with the mark EN-GJS-400-18-LT in accordance with DIN standard EN1563 in actual conditions, and realizes the requirement of providing casting products for alpine regions.

2. The nodular cast iron prepared by the formula and the method has good low-temperature impact resistance.

3. The invention defines the metal material formula which can be realized in a standard foundry under the condition of defining the direction of low silicon and high carbon in a large frame of DIN standard, has low production cost and simple production method, is qualified by ABB in British at present, and enters the stage of batch supply.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to specific examples below. It should be understood that the description is intended to be exemplary only, and is not intended to limit the scope of the present invention. Moreover, in the following description, descriptions of well-known structures and techniques are omitted so as to not unnecessarily obscure the concepts of the present invention.

The invention relates to low-temperature impact resistant nodular cast iron which adopts the following components:

one, Q10 pig iron composition (%)

C	Si	Mn	S	P	The addition amount%
						>3.3	≤0.9	≤0.15	≤0.04	≤0.05	40--75

Second, scrap steel (ordinary low carbon steel) composition (%)

C	Si	Mn	S	P	The addition amount%
						＜0.3	≤0.3	≤0.3	≤0.04	≤0.05	25--60

Thirdly, the component (%) granularity of the nodulizer is 5-25 mm

Mg	Ca	RE	Si	Ba	The addition amount%
						6-7	2-3	0.5-1.5	43-48	1-3	1.0-3.0

Fourthly, the granularity of the long-acting inoculant component (%) is 3-8 mm

	Ca	Al	Si	The addition amount%
						1.4-2	1.0-1.6	63-68	0.2-1.5

Fifthly, the specific inoculant has the component (%) 1# granularity of 0.1-1 mm

Si	Ca	Al	Bi	RE	The addition amount%
						60-78	0.8-1.5	0.4-1.9	0.7-1.1	1.0-2.3	0.1-1.0