News Detail

What is Q235 Carbon Steel ?

Issuing time:2024-04-08 10:18

Q235 Steel (Q235A Q235B Q235C Q235D)

Q235 steel is a plain carbon structural steel which is widely used in China, Q235 material in Chinese standard GB/T 700 is divided into 4 quality grades: Q235A, Q235B, Q235C and Q235D; Density of this steel is 7.85 g/cm3, tensile strength is 370-500 MPa; yield strength is 235 MPa (data are for steel bar or steel plate diameter ≤ 16mm). Since it’s mild steel, it is used directly without heat treatment.

Meaning and Designation

“Q” is the first letter of Chinese spelling of “Qu Fu Dian”, which means Yield Point.

“235” refers to the minimum yield strength 235 MPa tested with steel diameter ≤ 16mm.

Features and Applications

Q235 steel has good plasticity, toughness and weld ability, as well as a certain strength, good cold bending performance. Q235 material is usually rolled into wire rod or round steel, square steel, flat steel, angle steel, I beam, channel steel, other sections and steel plates. These products are widely used in construction and engineering welded structures, to make steel bars or build factory buildings, high voltage transmission towers, bridges, vehicles, boilers, containers, etc., and also used as a mechanical part with less demanding performance such as less stressed rods, connecting rods, screws, nuts, ferrules, brackets, and stands, etc.

Q235A, Q235B, Q235C, Q235D Steel Chemical Composition

The table below lists Q235 material chemical composition based on heat analysis.

Chemical Composition (heat analysis), %, ≤

Steel Grade

Quality Grade

C

Si

Mn

P

S

Deoxidation Method

Q235

Q235A

0.22

0.35

1.4

0.045

0.05

Rimmed / Killed

Q235B

0.2

0.35

1.4

0.045

0.045

Rimmed / Killed

Q235C

0.17

0.35

1.4

0.04

0.04

Killed

Q235D

0.17

0.35

1.4

0.035

0.035

Exceptionally Killed

Q235 Steel Properties

The following list summarizes Q235 steel properties including physical and mechanical properties.

Physical Properties

Notes:

· 10-6·K-1 = 10-6/K

· 1 Ω·mm²/m = 1 μΩ·m

· 1 g/cm3 = 1 kg/dm3 = 1000 kg/m3

· 1 GPa = 1 kN/mm2

· 1 MPa = 1 N/mm2

Physical Properties

Density, g/cm3

7.85

Melting point, ℃

about 1493

Specific heat capacity, J/(Kg·K)

470 at 20 ℃

Electrical resistivity, μΩ·m

about 0,15 (20 ℃)

Elastic modulus, GPa (kN/mm2)

200

Thermal conductivity, (W/m·K)

53-49 (0-100 ℃)

Coefficient of thermal expansion, (10-6/K)

11.3-11.6 (20 ℃)

Young’s modulus, GPa (kN/mm2)

200

Poisson’s ratio

0.24-0.28

Mechanical Properties

Yield strength and tensile strength are listed in the table below.

1 MPa = 1 N/mm2



Yield Strength (MPa, ≥); Thickness or Dia. (d) mm

Tensile Strength (MPa)

Steel Grade

Quality

d≤16

16< d ≤40

40< d ≤100

100< d ≤150

150< d ≤200

d≤100

Q235

Q235A

235

225

215

195

185

370-500

Q235B

Q235C

Q235D

Minimum Elongation



Elongation (≥ %); Thickness or Dia. (d) mm


Steel Grade

d≤40

40< d ≤60

60< d ≤100

100< d ≤150

150< d ≤200

Q235

26

25

24

22

21



Charpy impact (V notch)

Steel Grade

Quality

Temp. ℃

Impact energy (longitudinal, ≥ J)

Q235

Q235A

–

–

Q235B

20

27

Q235C

0

Q235D

-20

Bending Test Results of Q235 Material

Cold Bending Test 180° (B=2a)

Grade

Sample Orientation

Steel Dia. (d) of Curve Center

d≤ 60mm

60

Q235

Vertical

a

2a

Horizontal

1.5a

2.5a

Q235 Steel Equivalent

S235JRG2 and S235J2G4 are old designations in EN 10025:1993, S235JRG2 is replaced by the new designation S235JR (1.0038), and S235J2G4 replaced by S235J2 (1.0117) in EN 10025-2 since 2004.

You may be interested in Q235 vs A36, SS400, S235JR & E250 Steel;

Q235 vs Q195, Q215 and Q275 Steel

Q235 material equivalent to ASTM, ISO, European EN (German DIN EN, British BS EN, French NF EN…), Japanese JIS standard.

Note: Q235 India equivalent is E250 in Indian standard IS 2062.

图片1.png

Share to：