Specialized In Die Casting Service And Parts with Professional Design and Development

102,No.41,Changde Road,Xiaojiejiao,Humen Town,Dongguan,China | +86 769 8151 9985 | sales@hmminghe.com

The graphitization process of cast iron and the factors affecting the graphitization of cast iron

Publish Time: Author: Site Editor Visit: 2109


 1. Graphitization process of cast iron

    The formation process of graphite in cast iron is called graphitization process. The basic process of the structure of cast iron is the formation process of graphite in cast iron. Therefore, it is very important to understand the conditions and influencing factors of the graphitization process to master the structure and properties of cast iron materials.

    According to the dual state diagram of Fe-C alloy, the graphitization process of cast iron can be divided into three stages:

    The first stage is the liquid phase hypoeutectic crystallization stage. Including the direct crystallization of primary graphite from the liquid phase of hypereutectic components and the liquid phase of eutectic components to crystallize austenite plus graphite, graphite formed by decomposing primary cementite and eutectic cementite during high temperature annealing.

    The intermediate stage is the stage between eutectic transformation and hypoeutectoid transformation. Including the direct precipitation of secondary graphite from austenite and the graphite formed by the decomposition of secondary cementite in this temperature range.

    The third stage, that is, the transformation phase of the total discount. Including the eutectoid graphite formed during the co-folding transformation and the graphite formed by the decomposition of the eutectoid cementite during annealing.

2. Factors affecting graphitization of cast iron

    The structure of cast iron depends on the degree of graphitization. In order to obtain the required structure, the key is to control the degree of graphitization. Practice has proved that many factors such as the chemical composition of cast iron, the cooling rate of cast iron crystals, the overheating and standing of molten iron, etc., all affect graphitization and the microstructure of cast iron.

1. The influence of chemical composition

    Among the common C, Si, Mn, P, and S in cast iron, C and Si are elements that strongly promote graphitization, and S is an element that strongly hinders graphitization. In fact, the influence of each element on the graphitization ability of cast iron is extremely complicated. Its influence is related to the content of each element itself and whether it interacts with other elements, such as Ti, Zr, B, Ce, Mg, etc., all hinder graphitization, but if its content is extremely low (such as B, Ce<0.01%, T< 0.08%), they show the effect of promoting graphitization.

2. The effect of cooling rate

    Generally speaking, the cooling rate of castings tends to be slower, the more favorable it is for crystallization and transformation according to the state diagram of Fe-G stable system, and full graphitization; on the contrary, it is favorable for crystallization and transformation according to the state diagram of Fe-Fe3C metastable system. Finally obtained white iron. Especially in the graphitization at the eutectoid stage, since the temperature is low, the cooling rate increases, and the diffusion of atoms is difficult, it is generally difficult to fully progress the graphitization at the eutectoid stage.

    The cooling rate of cast iron is a comprehensive factor, which is related to the pouring temperature, the thermal conductivity of the molding material and the wall thickness of the casting. And usually these factors have basically the same impact on the two stages.

    Increasing the pouring temperature can delay the cooling rate of the casting, which promotes both the first stage of graphitization and the second stage of graphitization. Therefore, increasing the pouring temperature can pulverize graphite to a certain extent, and can also increase the eutectoid transformation.

3. The effect of overheating and high temperature standing of cast iron

    Within a certain temperature range, increasing the overheating temperature of the molten iron and extending the high-temperature standing time will result in the refinement of the graphite-based structure in the cast iron and increase the strength of the cast iron. If the superheat is further increased, the nucleation ability of the cast iron will decrease, and the graphite morphology will be deteriorated, and even free cementite will appear, which will decrease the strength, so there is a'critical temperature'. The critical temperature mainly depends on the chemical composition of the molten iron and the cooling rate of the casting. It is generally believed that the critical temperature of ordinary gray cast iron is about 1500-1550 ℃, so it is always hoped that the iron tapping temperature is higher.


Please keep the source and address of this article for reprinting: The graphitization process of cast iron and the factors affecting the graphitization of cast iron


Minghe Die Casting Company are dedicated to manufacture and provide quality and high performance Casting Parts(metal die casting parts range mainly include Thin-Wall Die Casting,Hot Chamber Die Casting,Cold Chamber Die Casting),Round Service(Die Casting Service,Cnc Machining,Mold Making,Surface Treatment).Any custom Aluminum die casting, magnesium or Zamak/zinc die casting and other castings requirements are welcome to contact us.

ISO90012015 AND ITAF 16949 CASTING COMPANY SHOP

Under the control of ISO9001 and TS 16949,All processes are carried out through hundreds of advanced die casting machines, 5-axis machines, and other facilities, ranging from blasters to Ultra Sonic washing machines.Minghe not only has advanced equipment but also have professional team of experienced engineers,operators and inspectors to make the customer’s design come true.

POWERFUL ALUMINUM DIE CASTING WITH ISO90012015

Contract manufacturer of die castings. Capabilities include cold chamber aluminum die casting parts from 0.15 lbs. to 6 lbs., quick change set up, and machining. Value-added services include polishing, vibrating, deburring, shot blasting, painting, plating, coating, assembly, and tooling. Materials worked with include alloys such as 360, 380, 383, and 413.

PERFECT ZINC DIE CASTING PARTS IN CHINA

Zinc die casting design assistance/concurrent engineering services. Custom manufacturer of precision zinc die castings. Miniature castings, high pressure die castings, multi-slide mold castings, conventional mold castings, unit die and independent die castings and cavity sealed castings can be manufactured. Castings can be manufactured in lengths and widths up to 24 in. in +/-0.0005 in. tolerance.  

ISO 9001 2015 certified manufacturer of die cast magnesium and mold manufacturing

ISO 9001: 2015 certified manufacturer of die cast magnesium, Capabilities include high-pressure magnesium die casting up to 200 ton hot chamber & 3000 ton cold chamber, tooling design, polishing, molding, machining, powder & liquid painting, full QA with CMM capabilities, assembly, packaging & delivery.

Minghe Casting Additional Casting Service-investment casting etc

ITAF16949 certified. Additional Casting Service Include investment casting,sand casting,Gravity Casting, Lost Foam Casting,Centrifugal Casting,Vacuum Casting,Permanent Mold Casting,.Capabilities include EDI, engineering assistance, solid modeling and secondary processing.

Casting Parts Application Case Studies

Casting Industries Parts Case Studies for: Cars, Bikes, Aircraft, Musical instruments, Watercraft, Optical devices, Sensors, Models, Electronic devices, Enclosures, Clocks, Machinery, Engines, Furniture, Jewelry, Jigs, Telecom, Lighting, Medical devices, Photographic devices, Robots, Sculptures, Sound equipment, Sporting equipment, Tooling, Toys and more. 


What Can we help you do next?

∇ Go To Homepage For Die Casting China

Casting Parts-Find out what we have done.

→Ralated Tips About Die Casting Services


By Minghe Die Casting Manufacturer |Categories: Helpful Articles |Material Tags: , , , , , ,Bronze Casting,Casting Video,Company History,Aluminum Die Casting |Comments Off

MingHe Casting Advantage

  • Comprehensive Casting design software and skilled engineer enables sample to be done within 15-25 days
  • Complete set of inspection equipment & quality control makes excellent Die Casting products
  • A fine shipping process and good supplier guarantee we can always deliver Die Casting goods on time
  • From prototypes to end parts, upload your CAD files, fast and professional quote in 1-24 hours
  • Wide-ranging capabilities for designing prototypes or massive manufacturing end use Die Casting parts
  • Advanced Die Casting techniques (180-3000T Machine,Cnc Machining, CMM) process a variety of metal & plastic materials

HelpFul Articles

The graphitization process of cast iron and the factors affecting the graphitization of cast iron

The formation process of graphite in cast iron is called graphitization process. The basic process o

Conditions for the realization of nodular cast iron casting without riser

1 The solidification characteristics of ductile iron The different solidification methods of nodula

Three Keys of Machining Technology of Iron Castings

The tool changes the process to a certain extent. As a tool for needles and brains, if we understand

The Casting Process Of Roulette Cast Iron Parts

Through the research on the casting process and material of the rolling plate of the medium and heav

The Ways To Solve The Special Problems Of Large Ductile Iron Castings

There are many types of large ductile iron parts, such as: large diesel engine block, large wheel hu

Three Kinds Of Smelting And Pouring Schemes For Ductile Iron

Furan resin sand is generally used as the molding material for large-scale ductile iron castings pro

Nodular cast iron smelting treatment process and matters needing attention

The alloying treatment of cast iron can be traced back to the 1930s and 1940s. The alloying treatmen

The Smelting Process Of Scrap Tempered Ductile Iron

In the traditional production process of ductile iron, about 10% of carbon scrap is generally used f

The Process Application Of Hot-Cold Iron On Castings

Chilled iron is a metal body placed outside the shell of precision castings; in the casting process,

Quick Identification Method Of Nodular Cast Iron Spheroidizing Quality

The inspection before the furnace of ductile iron is an indispensable part of the production process

The Main Technical Measures Of Low Cost Ironmaking

With the rapid development of China's iron and steel industry, China's annual pig iron production re

Typical Casting Defects Of Multiphase Ductile Iron Grinding Balls

The multiphase ductile iron grinding ball is a project product developed by the electromechanical re

Increase The Ferrite Content Of Ductile Iron

Studies have shown that different matrix structures have a greater impact on low-temperature impact

The Heat Treatment Process Of Cast Iron

In addition to the proper selection of excellent ingredients in the production of cast iron to obtai

Three Keys To Improve The Spheroidization Rate And Ductile Iron Graphite Roundness

Rare earth has two beneficial effects in molten iron: one is desulfurization and degassing, playing

The Process Control Of Vermicular Iron Production

Compared with gray iron, the tensile strength of vermicular iron is increased by at least 70%, the m

The Method And Application Of Sand-Coated Iron Mold Casting

Iron mold sand-coated casting is a casting process in which a thin layer of sand is covered on the i

The Methods To Improve Electromagnetic Pure Iron Wear Resistance

Electromagnetic pure iron is a widely used soft magnetic material. It has high magnetic induction an

The Anti-Corrosion Treatment Of Ductile Iron Pipe Fittings

Asphalt paint coating is used to transport gas pipelines. Preheating the pipe before painting can im

The Tempering And Quenching Of Cast Iron

The so-called quenching is to reduce the temperature of the material from the austenite region at a

The Current Status And Development Of Nodular Cast Iron And Spheroidizing Agent

Even in the economic downturn, ductile iron is still developing. Some people call ductile iron a win

The Anticorrosion Of Ductile Iron Pipe Zinc Layer

At present, nodular cast iron pipes use cement lining as the internal anti-corrosion form, and zinc

The Causes Of Common Defects In Gray Cast Iron Cylinder Blocks

The emergence of water glass has a history of more than 300 years, but as a binder for casting and c

The New Way To Purify Molten Iron

In particular, the rapid development of traditional and emerging industries such as automobile manuf

The Influence Of Overheating Environment On Austenitic Stainless Steel Pipe

Before it can be decomposed, the austenite is transformed into martensite until it is cooled below t

The Selection Of Stainless Steel In Corrosive Environment

When choosing stainless steel in a corrosive environment, in addition to having a detailed understan

Desulfurization Test Of Pure Iron Steel Ingot By Electroslag Smelting

Through experiments, it is found that carbon content at the bottom of the electroslag ingot will inc

The relationship between iron cost reduction and blast furnace production

In the increasingly fierce competition and the current difficult steel market situation, cost reduct

High-Strength Gray Cast Iron Smelting Technology

This article introduces how to obtain high-strength gray cast iron smelting technology under the con

Differences In The Solidification Characteristics Of Ductile Iron

Preventing shrinkage defects is often a very difficult problem in process design. In this regard, th

The Defects Caused By Medium Manganese Anti-Wear Ductile Iron

In the production of medium manganese anti-wear ductile iron parts, common casting defects include t

17 common defects in malleable iron castings

In the production of malleable iron castings, common casting defects include shrinkage cavity, shrin

The Main Technical Measures For Low-Cost Ironmaking

With the rapid development of my country's steel industry, my country's annual pig iron output reach

Effect Of Annealing Temperature On Chilled Low Chromium Molybdenum Ductile Iron Roll

Affected by the casting process, the chilled low chromium molybdenum ductile iron roll has a relativ

The Control Of Impurity Content In Manganese Iron Alloy

Out-of-furnace refining is an important part of the modern steel production process. The quality of

The Tempering Process Of Nodular Cast Iron

Quenching: heating at 875~925ºC temperature, holding for 2~4h, quenching into oil to obtain martensi

How to control the starting time of self-hardening furan resin sand under low temperature environment

Mainly studied the relationship between furan resin sand's usable time, mold release time and streng

Feeding Wire Method Ductile Iron Treatment Process

Through actual production, the punching method and the feeding method are used to produce ductile ir