Gray cast iron.
10 brands of gray cast iron are developed from the point of view
of durability (GOST 1412-9).
Gray cast irons are marked with letters and numbers SCH. SCH-series is cast
iron, and the numbers indicate the tensile strength of cast iron (
v
KGK/MM
2
).
Management of cast iron brands: S CH 15, S CH 18, S CH 20, etc.
Gray cast iron is used to make body details and details such as the bed frame.
Gray cast iron is obtained in vatranka.
Malleable cast iron.
These cast irons are obtained from white cast iron by
annealing them at high temperature. (Fe
3
C
3Fe +C). 7 brands of malleable cast iron
are produced: K CH 60-5; K CH 30-6; K CH 65-3 and others. The first numbers on the
stamp
indicate
v
, the second (after the line) number - , in %.
Malleable cast iron is
49
widely used in auto-tractor construction, agricultural machinery (reducer, crankcase,
bearing housings, etc.).
High strength cast iron.
According to GOST 7293-79, 9 grades of this cast iron
are developed: V CH 35, V CH 60, V CH 80, etc. Numbers on the stamp: the first is
v
, the second -
is indicated. This cast iron is used for heavy-duty parts: crankshaft,
piston rings, etc.
Control questions.
1. Graph of crystallization of pure metal l .
2. Characterize the compounds.
3. What is a state diagram?
4. Basics of drawing a GeS state diagram.
5. The structure of G and S.
6. What is eutectic?
7. Graph of melting of metals.
8. Ferrite - Perlite.
9. Austenite, cementite.
10. Ledeburit.
References.
1.
Ziyamukhamedova Umida. Materials science. Study guide. Tashkent:
Shafoat Nur Fayz, 2020. - 276 p.
2.
A. Matkarimov, F. Akhmadjonov "Materials science": textbook for students
of technical higher educational institutions of the Ministry of Higher and Secondary
Special Education; Ministry of Higher and Secondary Special Education of the
Republic of Uzbekistan, Center for Secondary Special Vocational Education.
Tashkent . " Teacher " NMIU , 2019. -80 p .
3.
Ziyamukhamedova UA Materials Science. Textbook. Tashkent - "Barkamol
Fayz Media" - 2019.
4.
Mirboboev VA and others. "Metal technology" Tashkent, 1991.
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