Applicable industry

Applicable industry

Shipbuilding

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The thick and large section ductile iron uses the special nodulating agent and the silicon rare earth inoculant

Casting’s specification

Casting weight: 14 tons
Material: QT400-18L
Spheroidization rate: > 80%
Mechanical properties: Tensile strength 350-400Mpa

Process and molten iron’s composition

 

The raw materials used in the production of low-temperature ductile iron shall qualify stringent composition control - with a low content of trace alloying elements, the Si content of 2.1-2.2% and the Mn content of below 0.15% (Mn<0.15%).

Raw molten iron’s composition:

C Si S Mn P AI
3.7700 1.3100 0.0100 0.1300 0.0280  

 

Product’s composition:

No.

C

Si

S

Mn

P

Al

Mg

1#

3.72

2.07

0.004

0.14

0.028

/

0.031

2#

3.7100

2.0500

0.0040

0.1400

0.0280

/

0.033

Test lug’s metallographs Metallography microstructure of cast sample

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Structure and mechanical properties

No.

Item

1#

2#

Comparison

1

Mechanical properties

Tensile strength/Yield strength/ Elongation percentage (fluctuation range for regular products)

The mechanical properties of products tested are within the fluctuation range for regular products, and qualify the requirements of customers.

 

 

382/242/23/132

386/244/18.5/133

 

2

Spheroidization  rate

Spheroidization rate (range)

The spheroidization rate is 90%-98%, and meet the requirements of customers.

 

 

90%-98%

90%-98%

 

3

－40℃ impact

Low temperature impact value (fluctuation range for regular products)

The low temperature impact values of products tested are within the fluctuation range for regular products, and qualify the requirements of customers.
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