High quality carbon structural steel hot rolled sheet steel and steel strips are used in the automotive, aviation and other sectors. The grade of its steel is boiling steel :08F, 10F, 15F; Killed steel :08, 08AL, 10, 15, 20, 25, 30, 35, 40, 45, 50. 

25 and below are low carbon steel plates, 30 and above are medium carbon steel plates.

NO.20 Carbon steel, the steel has low strength, good toughness, plasticity and weldability. The tensile strength is 355-500MPa, and the elongation is ≥24%.

Normalizing can promote spheroidization of the steel, refine large block proeutectoid ferrite, and improve the cutting performance of the embryo less than 160HBS.

No. 25 steel is a high-quality carbon structural steel with certain strength, hardness, plasticity and toughness.

Characteristics: High weldability and cold strain plasticity, medium machinability, poor hardenability and hardenability. Good strength and toughness after quenching and tempering at low temperature. No tendency to temper brittleness.

Product information:

No. 10 steel is a class of steel materials, its plasticity, toughness is very good, easy to form hot and cold processing, normal or cold processing after cutting performance is good, excellent weldability, no temper brittleness, hardenability and hardenability are poor.

Manufacturing requirements of the force is not large, high toughness parts, such as car body, storage, deep stamping utensils, pipes, gaskets, etc., can be used for cold rolling, cold punching, cold heading, cold bending, hot rolling and other processes, can also be used as the core strength is not high carburizing parts, carbonitriding parts, etc.

Chemical composition of 10# steel (%) :

(C) : 0.07% ~ 0.14%, (Si) : 0.17% ~ 0.37%, (Mn) : 0.35% ~ 0.65%, (S) : ≤0.04%, (P) : ≤0.35%, (Cr) : ≤0.15%, (Ni) : ≤0.25%, (Cu) : ≤0.25%.

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Carbon plate No. 20, chemical composition

No. 20 steel has a slightly higher carbon content, and the metallographic structure of both is pearlite + ferrite. The performance reflected in the performance is that the tensile strength and impact toughness of No. 20 steel are slightly higher, and basically there is no big difference between the two kinds of steel. Both kinds of steel are not quenched, heat treatment process is relatively simple, usually blank direct cutting or forging normalizing, for unimportant structural parts, connectors or stamping parts, or used as carburizing steel. There seems to be no 15 steel on the market, which can be replaced by 20 steel.

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No. 25 carbon steel plate, chemical composition: C :0.22~0.29, Si:0.17~0.37, Mn:0.50~0.80, S :≤0.035, P :≤0.035, Cr:≤0.25, Ni:≤0.30, Cu:≤0.25

Mechanical property

Tensile strength of sigma b (MPa) : 450 (46), or higher yield strength sigma (MPa) : s 275 (28), or higher elongation delta (%) : 23 or higher, reduction of area bits (%) : 50 or higher, impact energy Akv (J) : 71 or higher, impact toughness values of alpha kv (J/cm&sup 2) :≥88(9), hardness: no heat treatment ≤170HB

Sample size: 25mm

Heat treatment specification

Heat treatment specification: normalizing,870~890℃; Quenching,870℃; Temper,600℃.