alloy chrome casting steel balls, steel chromium casting balls

  • FOB Price : USD $950.00 / Piece
  • Minimum order:10
  • Place of Origin:China
Suizhou Gaincin Machinery Co.,Ltd(GAINCIN.com) cast iron grinding balls can be
divided into three categories including the high chromium type, medium chromium
type and the low chromium type.

1. The Quality Index of the High Chromium Type
The chromium content of the high chromium type product is greater than or equal to
10.0%. And the carbon content is between 1.80% and 3.20%. It is required by the
national standard that the hardness of the high chromium type product must be no
less than 58HRC, and that the impact value should be greater than or equal to
3.0J/cm2. This type of product must go through the hot quenching and the tempering
treatment to come up to the hardness.

Currently at home, there are two quenching methods for this type of product
including oil quenching and wind quenching. If the tested hardness of this type of
product is below 54HRC, then it shows that the quenching treatment is omitted.

2. The Quality Index of the Medium Chromium Type
The medium chromium type cast iron grinding ball is defined as the chromium
content ranging from 3.0% to 7.0%, and the carbon content coming between 1.80% and
3.20%. Its impact value should be no less than 2.0J/cm2. The national standard
requires the hardness of this type of product should be greater than or equal to
47HRC. For ensuring the quality, the medium chromium type product should be
processed with high temperature tempering to eliminate the casting stress.

If the surface of the steel ball assumes the dark red color, it proves that the
steel ball has been processed with high temperature tempering. If the surface of
the steel ball still comes with the metal color, then, we can judge that the steel
ball doesn’t go through the high temperature tempering treatment.

3. The Quality Index of the Low Chromium Type
Generally, the low chromium cast iron grinding ball contains the chromium with the
content of 0.5% to 2.5%, and the carbon with the content ranging from 1.80% to
3.20%. Accordingly, in line with the national standard, the hardness of the type
of product should be no less than 45HRC and the impact value should be no less
than 1.5J/cm2. The low chromium type product also needs the high temperature
tempering treatment to guarantee the quality. The treatment can eliminate the
casting stress. If the steel ball has dark red surface, it has gone through the
high temperature tempering treatment. If the surface still shows the metal color,
the steel ball is not treated with high temperature tempering.
The cast iron grinding ball is often applied for various rod mills in large scale
mine, cement plant, chemical plant, power station, quartz sand plant, silica sand
factory, etc.

Technological Production Process
Raw Material Inspection – Material Proportion – Intermediate Frequency Furnace
Heating and Smelting – Pouring via Steel Die – Quenching Treatment – Tempering
Treatment – Inspection – Packaging
Note 1. We make the falling ball impact fatigue test on the testing machine with
the standard height of 3.5m by using the product with the diameter of 100mm. The
impact fatigue life of the product with other diameters can be calculated by
reference to the following formula. Nx=Nx100/D N – The number of times. 2. The
impact toughness and the impact fatigue life are usually not taken as the basis of
delivery.

Surface Quality
The surface of the cast iron grinding ball is not allowed to have the casting
defects such as the crack, and the obvious gas porosity, inclusion, shrinkage
cavity, cold shut, elephant skin, etc.

Internal Quality
It is not allowed to have the shrinkage cavity, shrinkage porosity, gas porosity,
inclusion, and other cavity defects on the section cutting plane passing through
the pouring gate center and the ball center.

Testing Method and Inspection Rules
1. Impact Test The test is implemented by cutting the product through the pouring
gate to get the unnotched specimen of 1 Ommx1 Ommx55mm.

2. Rockwell Hardness Test Specimen Preparation Use the grinding machine to grind
the surface of the cast iron grinding ball until the flat surface appears with the
thickness of the part being ground off being 1.5mm to 5mm.

3. Chemical Composition Inspection When the pouring metal amount in the smelting
furnace exceeds 0.5t, the personnel should inspect the pouring metal in all the
smelting furnaces. When the pouring metal amount in the smelting furnace is less
than 0.5t, the personnel can check the smelting furnace one time in each work
shift. If one sample is unqualified, the re-inspection should be carried out with
the inspected sample doubled. If there is still unqualified sample, then, the
pouring metal in this batch of smelting furnaces is unqualified.

4. Surface Hardness Inspection Take the sample cast iron grinding balls with the
amount of no less than 5 from different parts of the heat treatment furnaces in
each batch. After the inspection, if there is one unqualified sample, then take
the products randomly with the amount doubled for re-inspection. If there is still
one unqualified sample, then, this batch of products is unqualified.

5. Internal Quality Inspection When continuously manufacturing every 100t product
of the same type, then select one product with the largest dimension randomly for
inspection. If the inspection result is disqualification, then, re-inspection with
the sample amount doubled should be carried out. If the chemical composition is
qualified, this batch of products is allowed to be processed with the heat
treatment again. If unqualified product still exists, then, this batch of products
is unqualified.

We can provide the most appropriate cast iron grinding balls in line with the
requirements of customers. Please contact us to get the detailed information.

Suizhou Gaincin Machinery Co., Ltd
Address: no.1704,economic and technical
development zone,Suizhou,P.R.China
E-mail:Info@gaincin.com
Kimy.Lee@gaincin.com
Candy.Wu@gaincin.com
Tel: 86-722-358 8806
Fax: 86-722-358 8806 x 8002
Website: www.gaincin.com
Showroom:gaincin.bossgoo.com

Suizhou Gaincin Machinery Co.,Ltd

1704,new economical and technical development zone, suizhou, hubei, P.R.China Tel: 86-722-3588806 Fax: 86-722-3588806 Country: China (Mainland)