(2) From the smelting process, to control the production quality of spheroidizing agent
Q: How to control the production quality of nodulizer?
In this issue, we learn how to control the smelting process
of nodularizing agent production.
The first is to add the order in the correct order.
Be careful not to let magnesium and scrap steel come into direct contact.
After the magnesium with a low melting point is melted,
it first reacts with silicon to form a Mg-Si phase to reduce
the burning loss of magnesium.
The second is to melt the composition to be uniform.
In addition to using the self-induction stirring of
the intermediate...
From the preparation of raw materials, to control the production quality of spheroidizing agent
Q: How to control the production quality of nodulizer?
At present, the rare earth nodularizing agents used in China
are mainly processed and manufactured according to
the pyrometallurgical method, the cored wire method,
and the mechanical mixing method.
The pyrometallurgical method is the basis of the latter method.
Using this method to produce nodulizer,
the quality control points have the following three aspects:
The first point: the preparation of raw materials:
Rare earth: It is best refined from rare earth ore with few impurities.
Metal...
The way to prevent hot cracking, you know?
How to solve the thermal cracking of gray cast iron?
It is characterized by a dark or almost black oxidized surface
at the crack, which can be found by visual inspection,
light transmission method, magnetic flaw detection,
pressure test, kerosene penetration and other methods.
Here are two ways to prevent thermal cracking:
one) Control reasonable chemical composition and try to
keep the sulfur content in the molten iron as low as possible
two) When pouring, avoid slag entering the cavity
Nanjing Difeng is committed to the production of nodularizing...
Learn how to maintain intermediate frequency furnace with the old furnace worker
Hello everyone, I am the youngest girl in the factory.
How does the intermediate frequency furnace
have a long service life?
one) The furnace lining material should have
the characteristics of high thermal strength,
low air permeability and low porosity.
two) The initial damage of the furnace lining is due to
the front-end erosion caused by the dissolution of the
sintered layer of the furnace lining refractory in the slag,
and the occurrence of cracks due to cyclic changes in temperature.
Another factor that causes crack propagation
in...
How to solve the gray cast iron hole defect
Hello everyone, I am the youngest girl in the factory.
How to solve the porosity of gray cast iron?
one) The charge should be properly managed.
For the charge with severe rust or a lot of grease on the surface,
it can only be used after cleaning or treatment.
two) For the charge with high gas content,
it should be remelted and regenerated before it can be used.
three) An appropriate amount of rare earth can be added
before the furnace for degassing
four) Control the appropriate molten iron release temperature
and pouring temperature
five) The hearth,...
Come on! Take a look at the production of strontium silicon inoculant
Hello everyone, I am the youngest girl in the factory.
Recently, orders have increased.
This is the produced silicon zirconium inoculant and silicon strontium inoculant,
which will be loaded and sent to customers soon.
Now the masters are producing orders for silicon strontium inoculant.
Come, let's take a look at the production process of
silicon strontium inoculant with me.
In the process of casting,
the silicon strontium inoculant plays a role in strong inking,
and its inking ability is significantly better than 75...
When to choose silicon-zirconium inoculant?
Q: How to choose an inoculant,
such as when to choose a silicon-zirconium inoculant?
The molten iron inoculation treatment is to add an inoculant to
the molten iron to change the metallurgical state of the molten iron
before the molten iron enters the casting cavity,
thereby improving the microstructure and properties of the cast iron.
Changes in the chemical composition of the molten iron
after the injection can be explained.
With the improvement of inoculation methods,
inoculation treatment has become an important means...
Provide a safe working environment for workers
Safe production starts from Nanjing Difeng
In the past two weeks, we have been doing safety inspections.
Usually factory production,
safety production ranks first,
to build a safe workplace for everyone.
For safe production,
we have made four requirements at Nanjing Difeng:
1. Do a good job in safety training,
improve the safety awareness of employees,
always have safety in mind,
always follow safety in operation,
and prevent the occurrence of safety accidents from the source.
2. Keep the production equipment in good operating...
When should silicontium inoculant be used?
Question: When is the silicon strontium inoculant mainly used?
Silicon strontium inoculant is suitable for thin-walled or
chilled high-sulfur and low-sulfur gray iron parts,
and can also be used in ductile iron to increase the number of ductiles,
especially high-nickel corrosion-resistant ductile iron
(containing Ni 14%, Cu 6%, Cr 2%, Si 1.5%).
It is also suitable for gray iron castings that require dense castings
without porosity and water pressure resistance.
Silicon-strontium inoculant,
also known as silicon-strontium...
Gray cast iron commonly used inoculation method
Today, I will take you to understand the characteristics of
inoculants with different ingredients
1. 75 Ferrosilicon: This is the most commonly used inoculant,
and the content of aluminum and calcium plays
an important role in the inoculation effect.
2. Strontium-containing ferrosilicon:
This kind of inoculant has a strong ability to eliminate white mouth,
which is especially beneficial to improve the shape and
distribution of graphite in thin-walled castings.
3. Barium-containing ferrosilicon:
This type of inoculant has a strong ability to...
Causes of Loose casting (below)
Hello everyone, I am the youngest girl in the factory.
Today, let's talk about it: the inoculant for
our king fried products from Nanjing Difeng.
At present, there are about 200 kinds of inoculants,
and there are more than 30 kinds of commonly used inoculants.
It is necessary to choose suitable inoculants for castings of different materials.
The wrong choice will cause some casting defects.
The types of inoculants are as follows:
1. Classification according to ingredients: silicon-based inoculants,
carbon-based inoculants, rare earth inoculants, etc.;
2....
Causes of Loose casting (Part 1)
Today, a foundry in the Hangzhou area encountered
the problem of loose castings.
The casting in question is a motor base product,
the material is required to be 250 grades,
the weight is 47 cents, the height is 47 cm,
and the wall thickness is 30 mm at the thick wall
and 7 mm at the thin wall.
According to the manufacturer's response,
the casting has always been loose in the thick wall recently,
and there is leakage under pressure.
In the production of gray cast iron,
white defects of thin-walled parts and loose defects
of...
Nanjingdifeng covered agent, you can choose at different particle size！
Hello everyone, I am the youngest girl in the factory.
Recently, many netizens have privately messaged me,
wanting to see the covering agent in our family.
Today, I will come to the factory to show you.
This is our all-covering agent product.
Due to its pure composition, reasonable and moderate specific gravity,
and strict particle size range,
our covering agent can greatly stabilize
the spheroidization process when used,
and can significantly improve the recovery rate of magnesium.
In addition, the covering agent is also conducive...
What are the other problems of vermicular graphite cast iron besides creep treatment?
Q: In addition to the problem of creeping treatment,
what are the other problems of vermicular graphite iron castings?
Hello everyone, I am the youngest girl in the factory.
In the production of vermicular graphite iron castings,
common casting defects include general defects of gray iron castings,
failure to creep, low creep rate, creep recession,
excessive white mouth, inoculation recession,
graphite floating, surface flakes Graphite layer,
slag inclusion, etc.
one, can't creep
If the triangle test piece in front of the furnace is found to...
Four suggestions to help you choose good quality spheroidizing agent
Q: How to choose good quality spheroidizer?
A good nodularizer is mainly reflected in the following points:
One, has a good affinity with sulfur and oxygen in molten steel,
and the reaction is small when placed in molten steel,
but the deoxidation effect and desulfurization effect are good!
Two, a good nodulizer can effectively improve
the graphite shape of cast iron.
In the cast iron industry, this role is particularly important.
Putting a good nodularizer in molten iron
can make the graphite shape gradually change from flake.
It is...
Do you want to know how to improve the spheroidization rate of nodular cast iron?
Today I would like to tell you:
a practical solution for improving the spheroidization rate of ductile iron
When the spheroidization rate is required to reach more than 90%,
the following measures can be adopted:
one、 Select high-quality charge to reduce
anti-spheroidizing elements in the charge.
Two、 Select a spheroidizer with low RE content to reduce
the effect of RE on the deterioration of the spherical graphite morphology.
Three、The S content of the original molten iron should be less than 0.020%,
which can reduce the consumption of nodularizing...
High temperature operation! Foundry, these must be paid attention to!
The continuous high temperature in July
was also a work challenge for the workshop masters.
So in high temperature production,
we still have to pay attention to safety.
1. Heatstroke prevention and cooling:
We reasonably arrange working hours,
do not start production at high temperature
in front of the furnace in the morning,
stop production in the afternoon when the temperature is high,
arrange workers to rest in the dormitory,
and start production after the temperature drops in the evening.
2. Personal...
Our inoculant, the whole process of production!
Hello everyone, I am the youngest girl in the factory.
The inoculants of Nanjing Dysprosium Peak are:
0.2-0.7mm, 0.5-1mm, 1-3mm, 3-8mm with different particle sizes.
At present, the workshop is producing silicon strontium inoculant.
The worker is adding raw materials with a good ratio to the medium frequency.
After melting to a certain temperature,
the molten iron will be poured into the round mold
specially containing the inoculant in the medium frequency furnace,
and cooled to form a After the solid, the inoculant is transported to
the...
Do you know what different inoculants do in casting?
Question: Do you know what role different inoculants play in casting?
3. Barium-containing ferrosilicon:
has a strong ability to promote graphitization,
can improve the shape and distribution of graphite in thin-walled castings,
and slow down inoculation and recession.
4. Zirconium-containing ferrosilicon:
Zirconium has a deoxidizing effect,
which is conducive to improving the fluidity of molten iron,
reducing the whitening tendency of cast iron,
and promoting uniform and fine A-type graphite.
5. Silicon-barium alloy: Using silicon-barium...
What are the inoculants?
Q: Do you know what inoculants are?
there are about 200 kinds of inoculants,
and more than 30 varieties of commonly used inoculants.
The categories of inoculants are as follows:
1. Classification according to ingredients:
silicon-based inoculants, carbon-based inoculants,
rare earth inoculants, etc.;
2. Classification according to the function of the inoculant:
stabilized inoculant, compound inoculant;
3. Classification according to the scope of use:
inoculant for gray cast iron, inoculant for ductile iron,
inoculant for vermicular graphite...
Do you know why spheroidization occurs
Hello everyone, I am the youngest girl in the factory.
In the actual production process,
there are many factors that cause poor spheroidization,
which are summarized as follows:
1. Poor quality of nodulizer
2. Improper operation of spheiroidzing treatment before furnace
3. The original molten iron has high sulfur content
or the molten iron is oxidized
4. Improper placement of molten iron ladle
or slow tapping of molten iron
5. The spheroidizing agent is added too early
or the molten iron is not poured out of the pit of the dam
6. The temperature of...
