阅读说明：本技术 一种珠光体球铁孕育剂 (Pearlite ductile iron inoculant ) 是由 翟广平 于 2019-09-25 设计创作，主要内容包括：本发明公开了一种珠光体球铁孕育剂,包括以下质量份数的物质：硅：70-80份,锰0.1-0.5份,铜：0.5-1份,磷：0.3-0.6份,锆:0.1-0.3份,铬：0.05-0.08份,铝：0.1-0.3份,钙：0.03-0.05份以及锡：0-18份,余量为铁。本发明的珠光体球铁孕育剂添加锡元素,由于锡原子体积比铁大,易引起晶格歪扭从而阻碍位错运动,提高球墨铸铁的稳定性,石墨化过程被抑制使得珠光体含量提高,同时提高球墨铸铁的抗拉强度和硬度。(The invention discloses a pearlite ductile iron inoculant which comprises the following substances in parts by weight: silicon: 70-80 parts, 0.1-0.5 part of manganese, copper: 0.5-1 part, phosphorus: 0.3-0.6 part, 0.1-0.3 part of zirconium, and the weight ratio of chromium: 0.05-0.08 parts of aluminum: 0.1-0.3 part, calcium: 0.03-0.05 parts and tin: 0-18 parts of iron and the balance of iron. The pearlite ductile iron inoculant disclosed by the invention is added with tin elements, and tin atoms are larger than iron in volume, so that lattice distortion is easily caused, dislocation motion is blocked, the stability of the ductile cast iron is improved, the graphitization process is inhibited, the pearlite content is increased, and meanwhile, the tensile strength and hardness of the ductile cast iron are improved.)

1. A pearlite ductile iron inoculant is characterized in that: the feed additive comprises the following substances in parts by mass: silicon: 70-80 parts, 0.1-0.5 part of manganese, copper: 0.5-1 part, phosphorus: 0.3-0.6 part, 0.1-0.3 part of zirconium, and the weight ratio of chromium: 0.05-0.08 parts of aluminum: 0.1-0.3 part, calcium: 0.03-0.05 parts and tin: 0-18 parts of iron, and the balance of iron;

the inoculant preparation method comprises the following steps: weighing the raw materials according to the proportion, and crushing the raw materials into small pieces; uniformly mixing the crushed raw materials, putting the mixture into a vacuum electric furnace, introducing argon and helium, heating to 1000-1500 ℃, smelting for 10-15min, and continuously stirring in the smelting process until the raw materials are uniformly mixed; after the raw materials are fully melted, the cast ingot is cooled and then crushed and granulated, and the granulation particle sizes are respectively 20-30mm, 10-20mm and 0.5-1.5 mm;

the inoculant is used for smelting the nodular cast iron through three times of inoculation:

first inoculation treatment: the particle size of the inoculant is 20-30 mm; the tin content of the inoculant is less than 5 percent;

and (3) second inoculation treatment: the particle size of the inoculant is 10-20 mm; the tin content of the inoculant is less than 10 percent;

and (3) third inoculation treatment: the grain size of the inoculant is 0.5-1.5 mm; the tin content of the inoculant is more than 15 percent.

2. The pearlite ductile iron inoculant of claim 1, wherein: the inoculant is prepared by introducing argon and helium in a volume ratio of 7: 3.

3. The pearlite ductile iron inoculant of claim 1, wherein: when the nodular cast iron is smelted at high temperature and taken out of a box, the tin content of the inoculant in the cast iron is more than 0.08 percent.

4. The pearlite ductile iron inoculant of claim 1, wherein: when the nodular cast iron is smelted and taken out of a box at high and low temperatures, the tin content of the inoculant in the cast iron is less than 0.012 percent.

Technical Field

The invention relates to a pearlite ductile iron inoculant.

Background

The inoculant has the advantages of promoting graphitization, reducing chilling tendency, improving graphite form and distribution condition, increasing eutectic group number, refining matrix structure, rounding ductile iron graphite, reducing or eliminating chilling, preventing the formation of surface free cementite, homogenizing structure, improving mechanical property and the like, and is widely applied to the field of cast iron.

The prior ferrosilicon inoculant is used as an inoculant for producing nodular cast iron, but the inoculant has small pearlite content to pearlite nodular cast iron, and the improvement of the strength is not obvious.

The invention aims to prepare a pearlite ductile iron inoculant.

Disclosure of Invention

The present invention has been made to solve the above problems, and an object of the present invention is to provide a pearlite ductile iron inoculant.

In order to achieve the purpose, the invention is realized by the following technical scheme: the pearlite ductile iron inoculant comprises the following substances in parts by mass: silicon: 70-80 parts, 0.1-0.5 part of manganese, copper: 0.5-1 part, phosphorus: 0.3-0.6 part, 0.1-0.3 part of zirconium, and the weight ratio of chromium: 0.05-0.08 parts of aluminum: 0.1-0.3 part, calcium: 0.03-0.05 parts and tin: 0-18 parts of iron, and the balance of iron;

the inoculant preparation method comprises the following steps: weighing the raw materials according to the proportion, and crushing the raw materials into small pieces; uniformly mixing the crushed raw materials, putting the mixture into a vacuum electric furnace, introducing argon and helium, heating to 1000-1500 ℃, smelting for 10-15min, and continuously stirring in the smelting process until the raw materials are uniformly mixed; after the raw materials are fully melted, the cast ingot is cooled and then crushed and granulated, and the granulation particle sizes are respectively 20-30mm, 10-20mm and 0.5-1.5 mm;

the inoculant is used for smelting the nodular cast iron through three times of inoculation:

first inoculation treatment: the particle size of the inoculant is 20-30 mm; the tin content of the inoculant is less than 5 percent;

and (3) second inoculation treatment: the particle size of the inoculant is 10-20 mm; the tin content of the inoculant is less than 10 percent;

and (3) third inoculation treatment: the grain size of the inoculant is 0.5-1.5 mm; the tin content of the inoculant is more than 15 percent.

Furthermore, the inoculant is prepared by introducing argon and helium in a volume ratio of 7: 3.

Furthermore, when the nodular cast iron is smelted at high temperature and taken out of a box, the tin content of the inoculant in the cast iron is more than 0.08 percent.

Particularly, when the nodular cast iron is smelted and taken out of a box at high and low temperatures, the tin content of the inoculant in the cast iron is less than 0.012 percent.

The invention has the beneficial effects that: the pearlite ductile iron inoculant disclosed by the invention is added with tin elements, and tin atoms are larger than iron in volume, so that lattice distortion is easily caused, dislocation motion is blocked, the stability of the ductile cast iron is improved, the graphitization process is inhibited, the pearlite content is increased, and meanwhile, the tensile strength and hardness of the ductile cast iron are improved.

Detailed Description