Brinell Hardness Test

Brinell Hardness Test

Test principle of Brinell hardness

The calculation formula of Brinell hardness is:

Among them, the unit of HB is kgf/
d——Indentation diameter, mm; h——Indentation depth, mm.
As long as the diameter of the indentation is measured, the HB value can be obtained by calculation or look-up table.

During the test, choose different loads and steel ball diameters according to the nature and shape of the material.

The advantages of the Brinell hardness test are strong representativeness, good data repeatability. At the same time, there is a certain conversion relationship with strength. The disadvantage is that harder materials cannot be tested; the indentation is large and not suitable for finished product inspection. It is usually used to test the hardness of raw materials and tempered parts, such as cast iron, non-ferrous metals, low alloy steel, etc.

 

Test conditions

In the Brinell hardness test, we should select the diameter (D) of the indenter sphere, the test load (F), and the load holding time (t), according to the type of metal material, the range of hardness values ​​and the thickness. There are five commonly used indenter diameters of 1, 2, 2.5, 5 and 10 mm.
The test load can range from 9.807N (1kgf) to 29.42 KN (3000 kgf).
The load holding time is generally 10-15s for ferrous metals; 30s for non-ferrous metals; 60s when the HB value is less than 35.

 

Pros and Cons

The diameter of the steel ball and the indentation left on the surface of the metal material is large. Therefore, the measured hardness value is more accurate. There is a certain relationship between HB value and tensile strength. That means we can determine the tensile strength of metal materials approximately according to the Brinell hardness value.
If the hardness of the metal is too high, it will affect the accuracy of the hardness value. Therefore, the HB test is generally suitable for measuring metal materials with a HB value of less than 650.
The Brinell hardness indentation is relatively large, so it is not suitable to measure finished products and sheet materials.

Yide casting is a leading casting foundry in China, we produce quality casting products, pursuing details required for every casting product, we have an imported testing machine to check the Brinell hardness and other parameters, committed to proving the best casting service for our casting customers.

ASTM A48 Standard for Gray Iron Castings

ASTM A48 Standard for Gray Iron Castings

ASTM A48 / A48M Standard Specification for Gray Iron Castings, grades including Class No. 20, 25, 30, 35, 40, 45, 50, 55, 60.

Class No. 20 A, 20 B, 20 C, 20 S,
Class No. 25 A, 25 B, 25 C, 25 S,
Class No. 30 A, 30 B, 30 C, 30 S,
Class No. 35 A, 35 B, 35 C, 35 S,
Class No. 40 A, 40 B, 40 C, 40 S,
Class No. 45 A, 45 B, 45 C, 45 S,
Class No. 50 A, 50 B, 50 C, 50 S,
Class No. 55 A, 55 B, 55 C, 55 S,
Class No. 60 A, 60 B, 60 C, 60 S.

This specification covers general engineering gray iron castings mainly used for tensile strength. The castings are classified according to the tensile strength of the cast iron in the individually cast test rods.

1. Requirements for Tensile Strength

On the above chart, you can see that each material grade requires its minimum value of tensile strength, ksi. That means the tensile strength is the most important specification for gray iron castings.

However, there is no need to write A, B, C, S material grades for the foundry. Because A, B, C, and S are only requirements for test bar.

For example, for a cast iron plant, ASTM A48 Class 20 will be sufficiently detailed, which means the minimum value. The tensile strength of gray cast iron must be higher than 20 ksi (138 Mpa).

ASTM A48 Class 20: Min. Tensile Strength 20 ksi (138 Mpa)
ASTM A48 Class 25: Min. Tensile Strength 25 ksi (172 Mpa)
ASTM A48 Class 30: Min. Tensile Strength 30 ksi (207 Mpa)
ASTM A48 Class 35: Min. Tensile Strength 35 ksi (241 Mpa)
ASTM A48 Class 40: Min. Tensile Strength 40 ksi (276 Mpa)
ASTM A48 Class 45: Min. Tensile Strength 45 ksi (310 Mpa)
ASTM A48 Class 50: Min. Tensile Strength 50 ksi (345 Mpa)
ASTM A48 Class 55: Min. Tensile Strength 55 ksi (379 Mpa)
ASTM A48 Class 60: Min. Tensile Strength 60 ksi (414 Mpa)

If you want to know the equivalent grades of other standards, please refer to the equivalent grades of gray iron and ductile iron.

2. Dimension Requirements

The castings should conform to the dimensions or drawings provided by the purchaser. If there is no drawing, it shall conform to the predicted size of the pattern equipment provided by the purchaser.

Usually, the buyer should provide 3D drawings and 2D drawings. 3D engineering drawings will make patterns more accurately. The 2D engineering drawing will provide detailed dimensional tolerances and processing requirements. Therefore, this will avoid confusion and misunderstanding, and drawings are the only standard for dimensions.

If the purchaser does not have a drawing, he should provide an original sample. Our Yide Casting can scan samples into 3D engineering drawings, so the size of the samples will become the standard. The problem is that the casting foundry should ask the buyer for the tolerance of the key dimensions, because the sample cannot show the tolerance range in the drawing.

3. Quality and Defects Requirements

There should be no visible sand, scale, cracks and thermal cracks on the surface of the casting.

Unless the purchaser’s written permission is obtained, repairs shall not be carried out by any form of splicing or welding.

Generally, the foundry should have enough experience to deal with defects. However, when there is a defect, the foundry should discuss with the purchaser to confirm whether leak plugging and welding can be carried out.

For metal castings, defects on the surface and internal areas are inevitable, so it is essential for the foundry to conduct good quality inspections and communicate with customers in a timely manner. If you want to know the appearance of casting defects, please refer to Yide Casting’s article: Photos of casting defects.

4. Cast Test Rods

The test rod should be an independent casting of the same batch as the representative casting, and have the dimensions shown in Table 4. You can leave a margin for a reasonable template draft within the tolerance range shown in Table 4. Test rods A, B and C are all standard test rods in the form of simple cylinders. The test rod S is special and is intended to be used where the standard rod is not satisfactory.


5. Special Requirements

If a written agreement is reached between the manufacturer and the purchaser, the casting may have to meet special requirements regarding hardness, chemical composition, microstructure, pressure tightness, radiographic robustness, size, surface finish, etc.

This means that buyers may ask for more if necessary. ASTM A48 is only the standard for the main mechanical properties of gray cast iron. If the buyer has the above-mentioned special requirements, he should inform the manufacturer at the beginning.

6. Mechanical Properties of Gray Iron Castings

Grade 20, 25, 30 and 35 gray cast irons have excellent machinability, high damping capacity, low modulus of elasticity and relatively easy manufacturing.

Grade 40, 45, 50, 55, and 60 gray cast irons are generally more difficult to machine, have lower damping capacity, higher modulus of elasticity, and are more difficult to manufacture.

Higher grade means higher tensile strength, higher hardness, higher price and difficulty of production, so you must know which material grade is suitable or sufficient for your project without having to pursue the highest grade.

Yide casting is a leading casting foundry in China, specialized in iron casting and machining, can meet kinds of requirements of your casting products, if you are looking for experienced iron foundry, please feel free to contact us for more details.

iron casting car flange

ASTM A126 Standard Specification

ASTM A126 Standard Specification

Today, we will introduce the ASTM A126 Standard specification for gray iron castings, such as valves, flanges and pipe fittings. This specification covers three classes of gray iron for castings, please see as the following chart.

Tensile Requirements of ASTM A126

 1.Class A2. Class B3. Class C
Tensile strength, min, ksi (MPa)21 (145)31 (214)41 (283)
ASTM A48 Equivalent gradesNO. 25NO.30, 35NO. 40

Castings should be manufactured in a manner similar to workers. In addition, the surface should be free of visible sand, scale, cracks and thermal cracks.

Chemical analysis should be carried out for each batch of products and should meet the following relevant content requirements: The maximum phosphorus content is 0.75%, and the maximum sulfur content is 0.15%.

iron casting car flange

Yide Casting is a professional iron foundry in China, with 28 years’ casting and machining experience, provides ductile iron cast, gray iron cast, brass iron cast services for our customers, you only need to show us your drawing file and requirements, we will ensure the final solution and send you a cast sample to check the quality and parameters, if you are looking for professional casting foundry, please don’t hesitate to contact us for more details.

Spheroidizing Treatment Method of Ductile Cast Iron

Spheroidizing Treatment Method of Ductile Cast Iron

There are many spheroidizing methods for ductile iron castings. And the pour-over modification process is currently the most widely used spheroidizing method all over the world.

The treatment package used is usually a dam type spheroidizing treatment package. In order to reduce the intensity of the reaction between molten iron and magnesium, and the volatilization rate of magnesium vapor, the pour-over treatment process usually uses an alloy nodulizing agent with a lower magnesium content.

The process of spheroidizing treatment of ductile iron castings including the following steps.

First, put the nodulizing agent into one side of the dam, and cover the top with ferrosilicon alloy. And then cover it with rust-free iron filings, steel plate or other covering agent. When spheroidizing, the molten iron should be flushed into the other side of the molten iron ladle as much as possible.

The absorption rate of magnesium in the flushing method is generally 30% to 50%. There are three ways to improve the spheroidizing effect.

1. Increasing the ratio of the height to the diameter of the treatment package.

2. Adopting low-magnesium alloy spheroidizing agent.

3. Reasonable molten iron temperature and covering dosage.

The advantages of the pour-over method are simple processing and equipment, easy operation, greater flexibility in production, and low technical content required. However, the disadvantage is that the spheroidization process is higher pollution by magnesium light and smoke, and the absorption rate of magnesium is low.

There is also a subcontracting method, which uses pure magnesium as a nodulizing agent.

The subcontracting method is suitable for processing molten iron with high sulfur content. At the same time, this method can better separate impurities such as magnesium sulfide and silicate from the molten iron. The reaction with molten iron is not very violent and the temperature of molten iron is less. Therefore, it is safe to use, and the absorption rate of magnesium can reach 60% to 80%.

The specific process flow contains the following steps.

1. Before the spheroidizing treatment, place the subcontractor horizontally.

2. Inject quantitative molten iron, and then add the nodulizing agent to the reaction chamber.

3. Lock the closing device, and then close the ladle cover.

4. Turn the molten iron ladle to stand upright.

By now, the molten iron enters the reaction chamber through the small holes in the reaction chamber. The flow rate is related to the area of ​​the small holes and the static pressure in the molten iron ladle.

Magnesium vaporizes by heating, forming a magnesium vapor pressure in the reaction chamber. When the pressure exceeds the static pressure of the molten iron in the ladle, the molten iron stops entering, and the latent heat of vaporization of magnesium reduces the temperature in the reaction chamber. And the vapor pressure also drops, and the molten iron enters the reaction again. This kind of automatic adjustment can make magnesium react with molten iron more smoothly.

The spheroidizing process of the subcontracting method also produces large magnesium light and smoke, and the small holes in the reaction chamber in the subcontracting are easily blocked by molten iron or molten slag. It is troublesome to clean and maintain the size of the small holes. The spheroidizing method is difficult to continuously process the molten iron.

Yide Casting is a professional iron foundry in China, with 28 years’ casting and machining experience, provides ductile iron cast, gray iron cast, brass iron cast services for our customers, you only need to show us your drawing file and requirements, we will ensure the final solution and send you a cast sample to check the quality and parameters, if you are looking for professional casting foundry, please don’t hesitate to contact us for more details.

Ductile Iron EN-GJS-400-18

Mechanical Properties of Ductile iron EN-GJS-400-18:

The minimum tensile strength of EN-GJS-400-18 is 400 Mpa; the minimum yield strength is 250 Mpa; and the minimum elongation is 18%.

The matrix of this grade is completely ferrite, with high ductility and impact strength. Therefore, it can be used at a temperature of -20°C. In addition, heat treatment is part of the manufacturing process.

EN-GJS-400-18 ductile iron can ensure notched impact toughness at -20°C. In terms of safety, it has more advantages than cast steel. Cast steel is prone to cracking due to its extremely high shrinkage. One of the reasons is the expansion caused by the graphite spheres formed in the ferrite matrix. This expansion offsets the shrinkage of the material (which is low anyway), thereby preventing cracking.

This grade of ductile iron has a minimum elongation at break of 18%. And due to its high ductility, it is also suitable for low temperature applications. As early as 1980, Dr. Betschart determined the allowable stress of ductile cast iron in his thesis entitled “Research in Modern Cast Metal for Structures”.

Applications of Ductile iron EN-GJS-400-18:

Ductile cast iron EN-GJS-400-18 is suitable not only for the production of safety components for cable cars and ski lifts in high mountain areas, but also for the production of heavy chassis components, automobile crankshafts and wheels.

This material is also widely used in the production of iron castings for wind power, forestry and contractor machinery, valves, brakes,, consoles, pressure tanks, high-pressure equipment housings, and cooling components. And when the temperature is as low as -20ºC, where the impact strength needs to be guaranteed.

Due to its many advantages, the “modern form” of ductile iron has largely replaced cast steel.

The Differences between Cast Iron and Cast Aluminum

The Differences between Cast Iron and Cast Aluminum

Due to the different materials, the distinction between cast aluminum and cast iron is quite obvious. Today, Yide Casting will share the differences with you, so that you can choose the right material for your castings.

  • The difference in weight

The specific gravity of cast aluminum is lighter than cast iron. The density of cast iron is about 7.8 g/cm3, while the density of cast aluminum is about 2.7g/cm3. The weight of cast aluminum parts of the same size is obviously lighter.

  • The difference in volume

The specific gravity of aluminum is lighter. At the same time, the structural strength of aluminum castings per unit volume is less than that of iron castings.Thus the volume of aluminum castings with the same strength is larger than that of iron castings. In the case of the same volume, the strength of cast aluminum is lower than that of cast iron.

  • The difference in cost

The current market price of cast aluminum is much higher than cast iron.

  • The difference in heat dissipation

The thermal conductivity of cast aluminum parts is more than three times that of cast iron parts. It has been widely used in radiators and heat exchangers in industry and cooking utensils.

  • The difference in corrosion resistance

The surface of aluminum castings has a corrosion-resistant oxide protective film, which protects aluminum castings from corrosion. Therefore, aluminum castings are also widely used in medical equipment, refrigeration equipment, oil and gas pipelines, petroleum machinery, etc. The corrosion of iron castings is far less than that of aluminum castings.

  • The difference in casting performance

The casting performance of aluminum is higher than that of cast iron. Aluminum is easy to cast and can cast rough castings with complex shapes.

Yide casting is an experienced casting foundry, specialized in casting iron for 28years, can manufacture the casting iron parts according to your drawing file and requirement. If you are looking for a casting manufacturer, please feel free to contact us for more details, and you are welcome to visit our factory for more details.

iron casting fulcrum bearing

BS2789 Grade 420-12 SG Iron

BS2789 Grade 420-12 SG Iron

BS2789 Grade 420-12 SG Iron is not a common grade material.  We use ASTM A536 65-45-12 instead normally.

It is related to BS EN 1563 GJS 420-12; 60-40-10; 65-45-12; FGS420-12; SF400; SFP400; DIN 1693 ISO 185 250.

Properties of 420-12 SG Iron

Tensile strength ≥ 420Mpa.
Elongation ≥ 12%.

Mechanical properties shown are typical and may vary subject to the size and section of this SG iron grade.

Certification BS2789 420-12 S G Iron is available with a certificate or conformity, please request when placing any orders.

The hardness of 420-12 SG Iron

The hardness of this grade is around 212 Brinell hardness.

Chemistry composition of 420-12 SG Iron

Carbon 3.40-3.85%

Phosphorous 0.10% max

Manganese 0.10-0.30%

Sulphur 0.02% max

Silicon 2.30-3.10%

Magnesium 0.07% max

 

Foundry of 420-12 SG Iron

BS2789 Grade 420-12 is suitable for applications where the optimal impact, fatigue, electrical conductivity and magnetic permeability features。

Typical applications include valves, dies, pistons and moulds.

iron casting fulcrum bearing cast iron Forklift base

 

Yide casting is an experienced casting foundry, specialized in casting iron for 28years, can manufacture the casting iron parts according to your drawing file and requirement. If you are looking for a casting manufacturer, please feel free to contact us for more details, and you are welcome to visit our factory for more details.

 

 

Ductile Iron EN-GJS-450-10/ASTM A536 65-45-12

Ductile Iron EN-GJS-450-10/ASTM A536 65-45-12

Ductile Iron EN-GJS-450-10/ASTM A536 65-45-12 is an excellent grade material.

This grade is equal to QT450-10 in China; GS400-12 in Italy; FCD400 in Japan; FGS400 in France; FNG42-12 in Belgium; SJK-400 in Norway and ISO 1083 450-10.

Yide Casting has producing this material grade for many years. Herein, we will share the mechanical properties, chemical composition, foundries and castings of EN-GJS-450-10 for you.

Properties of EN-GJS-450-10 cast iron

Tensile strength ≥ 450 Mpa.
Yield strength ≥ 310 Mpa.
Elongation ≥ 10%.
As for A536 65-45-12, its elongation ≥ 12%. And the other properties are the same as EN-GJS-450-10

Ductile cast iron EN-GJS-450-10 has high tensile strength, high elongation, and good impact resistance.  Therefore, this grade is very widely used.

Hardness of EN-GJS-450-10 cast iron

The hardness of this ductile cast iron grade is between 160-210 Brinell hardness.

Chemistry composition of EN-GJS-450-10 cast iron

According to the standard DIN EN 1563, the foundries could adjust the chemical composition as long as the mechanical and physical properties of the castings could meet the requirements in Standards.

The following chart is an approximate chemical composition range for your reference.

C: 3.50-4.00, Si: 2.20-2.90, Mn: 0.3-0.6, P: 0.03-0.06, S: 0.02-0.040, Mg: 0.020-0.060.

DIN EN 1563ISOC %Si %Mn %P %S %Mg %
EN-GJS-450-10450-103.5-42.2-2.90.3-0.60.3-0.60.02-0.040.02-0.06

Foundry of EN-GJS-450-10 cast iron

Because of the comparatively high elongation, EN-GJS-450-10 ductile iron could be used for producing impact resistance casting parts. In addition, it has good low temperature impact resistance and good hardness. Thus it has been used for producing plough, plough pile, differential shell, plow point, valve body and high pressure cylinder.

cast iron shell Wheel hub shell Wheel hub shell

 

 

 

 

Yide casting is an experienced casting foundry, specialized in casting iron for 28years, can manufacture the casting iron parts according to your drawing file and requirement. If you are looking for a casting manufacturer, please feel free to contact us for more details, and you are welcome to visit our factory for more details.

 

 

Introduction to Brinell Hardness

Brinell hardness is a standard that indicates the hardness of a material. Measured by Brinell hardness tester. It was first proposed by the Swede J.A. Brinell, thus called Brinell hardness.

Press a hardened steel ball with a diameter of D into the surface of the metal material to be tested with a certain load P. And then remove the load after holding it for a period of time. The ratio of the load P to the surface area F of the indentation is the Brinell hardness value, denoted as HB.

Introduction to brinell hardness

Brinell hardness (HB) is generally used when the material is soft. For example, non-ferrous metals, steel before heat treatment or after annealing.

HB refers to pressing a hardened steel ball or cemented carbide ball of a certain diameter into the surface of the metal to be tested with a certain test load. Keep it for a specified time, then unload, and measure the diameter of the indentation on the tested surface.

 

Brinell Hardness Tester

Brinell Hardness Tester

Hardness range

The Brinell hardness range is 8~650HBW.

Features

Generally speaking, the smaller the HB value, the softer the material, and the larger the indentation diameter. Conversely, the larger the HB value, the harder the material, and the smaller the indentation diameter.

The advantage of HB measurement is that it has high measurement accuracy, large indentation area. Thus can reflect the average hardness of the material in a larger range. The measured hardness value is also more accurate, and the data is repeatable.

Symbol

The symbol of Brinell hardness is represented by HBS or HBW.

HBS means that the indenter is a hardened steel ball, which is used to determine materials with a Brinell hardness value below 450, such as mild steel, gray cast iron, and non-ferrous metals.

HBW indicates that the indenter is a cemented carbide and is used to determine materials with a Brinell hardness value below 650.

Brinell Hardness Testing Insight

How to express Brinell hardness

The number before HBS or HBW is the hardness value, and the following numbers are used to indicate the test conditions in sequence:

①The diameter of the sphere of the indenter;

②Test load;

③The time that the test load is maintained (10~15s are not marked).

For example, 170HBS10/1000/30 means that a steel ball with a diameter of 10mm is used. Under the test load of 9807 N (1000 kgf), the measured Brinell hardness value is 170 when kept for 30s.

530HBW5/750 means using a 5 mm diameter cemented carbide ball, under the test load of 7355N (750kgf), the measured Brinell hardness value is 530 when it is maintained for 10-15s.

Application

The HB measurement method is suitable for cast iron, non-ferrous alloys, various annealed and tempered steels. It is not suitable to measure samples or workpieces that are too hard, too small, too thin, and whose surface is not allowed to have large indentations.

Yide casting is an experienced casting supplier, specialized in casting iron for 28years, can manufacture the casting iron parts according to your drawing file and requirement. If you are looking for a casting manufacturer, please feel free to contact us for more details, and you are welcome to visit our factory for more details.

Auto pressure shell

Ductile Cast Iron EN-GJS-600-3

EN-GJS-600-3 ductile iron is a high grade material in European standard DIN EN 1563.

It is equal to GGG60 in DIN 1693, QT600-3 in China, A536 80-60-03 in USA ASTM, GS600-12 in Italy, FCD600 in Japan, FGS600-2 in France, FNG60-2 in Belgium, SJK-600 in Norway and ISO 1083 600-3.

Today, I will introduce the mechanical properties, chemical composition, foundries and castings of EN-GJS-600-3 for you.

Properties of EN-GJS-600-3 cast iron

Tensile strength ≥ 600 Mpa.
Yield strength ≥ 370 Mpa.
Elongation ≥ 3%.
No impact requirement.

Ductile cast iron EN-GJS-600-3 has high tensile strength, middle ductility and plasticity. It also has good wear resistance and shock absorption properties. That means its comprehensive material properties are very high.

It has good casting process performance. At the same time, it could be heat treated to improve the microstructure and mechanical properties.

Hardness of EN-GJS-600-3 cast iron

The hardness of this ductile cast iron grade is between 180-270 Brinell hardness.

Density of EN-GJS-600-3 cast iron

The density of this ductile iron grade is about 7.3 g/cubic centimeter, or 7.3 kg/liter.

Chemistry composition of EN-GJS-600-3 cast iron

According to the standard DIN EN 1563, the foundries could adjust the chemical composition as long as the mechanical and physical properties of the castings could meet the requirements in Standards.

The following chart is an approximate chemical composition range for your reference.

DIN EN 1563ISOC %Si %Mn %P %S %
EN-GJS-600-3600-32.5-3.61.8-2.80.3-0.7≤0.08≤0.02

Foundry of EN-GJS-600-3 cast iron

Yide casting is an experienced casting foundry, specialized in casting iron for 28years, can manufacture the casting iron parts according to your drawing file and requirement. If you are looking for a casting manufacturer, please feel free to contact us for more details, and you are welcome to visit our factory for more details.

cast iron flywheel cast iron part Auto pressure shell