Q420 Steel Chemical Composition, Properties, Specifications & Equivalent
Q420 Steel Introduction
Q420 steel is a Chinese steel grade of Low Alloy High Strength Structural Steel, Yield Strength is 420 MPa, parameters are tested with 16mm diameter steel bars or steel plates, and tensile strength is 520-680 Mpa, the material density is 7.85 g/cm3. According to GB/T 1591-2008, Q420 has 5 quality levels: Q420A, Q420B, Q420C, Q420D and Q420E. For Q420 steel equivalent, chemical composition and mechanical properties, please see the tables below content.
Features and Uses
Q420 steel has high strength, especially in normalized or normalized plus tempered state, with high comprehensive mechanical properties, can be used in large ships, bridges, power station equipment, medium and high pressure boilers, high pressure vessels, lifting machinery, mining machinery and other large welded structural parts.
Table-1, Chemical Composition of Q420 Steel
| Chemical Composition % (GB/T 1591 – 2008) | ||||||||||||||||
| Steel Grade | Grade | C (≤) | Si (≤) | Mn (≤) | P (≤) | S (≤) | Nb (≤) | V (≤) | Ti (≤) | Cr (≤) | Ni (≤) | Cu (≤) | N (≤) | Mo (≤) | B (≤) | Als (≥) |
| Q420 | Q420A | 0.20 | 0.50 | 1.70 | 0.035 | 0.035 | 0.07 | 0.20 | 0.20 | 0.30 | 0.80 | 0.30 | 0.015 | 0.20 | – | – |
| Q420B | 0.035 | 0.035 | – | |||||||||||||
| Q420C | 0.030 | 0.030 | 0.015 | |||||||||||||
| Q420D | 0.030 | 0.025 | 0.015 | |||||||||||||
| Q420E | 0.025 | 0.020 | 0.015 | |||||||||||||
| Chemical Composition % (GB/T 1591 – 2018) | |||||||||||||||
| Steel Grade | Grade | C (≤) | Si (≤) | Mn (≤) | P (≤) | S (≤) | Nb (≤) | V (≤) | Ti (≤) | Cr (≤) | Ni (≤) | Cu (≤) | N (≤) | Mo (≤) | B (≤) |
| Q420 | Q420B | 0.20 | 0.55 | 1.70 | 0.035 | 0.035 | 0.05 | 0.13 | 0.05 | 0.30 | 0.80 | 0.40 | 0.015 | 0.20 | – |
| Q420C | 0.030 | 0.030 | |||||||||||||
Table-2, Carbon Equivalent Value (CEV)
Steel delivered in hot rolled state (based on smelting analysis)
| CEV (Mass fraction ≤%); Nominal thickness or diameter Ø | ||||||
| Steel Grade | Quality Grade | ≤ 30 | 30 < Ø ≤ 63 | 63 < Ø ≤ 150 | 150 < Ø ≤ 250 | 250 < Ø ≤ 400 |
| Q420 | Q420B | 0.45 (CEV) | 0.47 | 0.48 | 0.49 | – |
| Q420C | ||||||
Table-3, Q420 Steel Mechanical Properties (Hot rolled)
| Thickness or Dia. (Ø) mm; Yield Strength (≥N/mm2) | ||||||||||
| Steel Grade | Quality | Ø≤16 | 16< Ø ≤40 | 40 < Ø ≤63 | 63 < Ø ≤ 80 | 80 < Ø ≤ 100 | 100 < Ø ≤ 150 | 150 < Ø ≤ 200 | 200 < Ø ≤ 250 | 250 < Ø ≤ 400 |
| Q420 | Q420B | 420 | 410 | 390 | 370 | 370 | 350 | – | – | – |
| Q420C | ||||||||||
| Dia. (Ø) mm; Tensile Strength (N/mm2) | |||||
| Steel Grade | Quality Level | Ø≤100 | 100 < Ø ≤ 150 | 150 < Ø ≤ 250 | 250 < Ø ≤ 400 |
| Q420 | Q420B | 520 – 680 | 500 – 650 | – | – |
| Q420C | |||||
Table-4, Elongation
| Dia. (Ø) mm; Elongation (%) | |||||||
| Steel Grade | Sample direction | Ø≤40 | 40 < Ø ≤ 63 | 63 < Ø ≤ 100 | 100 < Ø ≤ 150 | 150 < Ø ≤ 200 | 250 < Ø ≤ 400 |
| Q420 | Horizontal | 20 | 19 | 19 | 18 | – | – |
| Vertical | 21 | 20 | 20 | 19 | – | – | |
Q420 steel equivalent to US ASTM, European EN, Germany DIN, Japan JIS, France NF, UK BS and ISO standard (For reference purposes only)
| China | USA | Germany | Japanese | France | UK | ISO | |||||||
| Standard | Grade | Standard | Grade | Standard | Grade | Standard | Grade | Standard | Grade | Standard | Grade | Standard | Grade |
| GB/T 1591 – 2008 | Q420A | ASTM A572M, ASTM A633M | Gr.60, Gr.E | NF A36-201 | E420-1 | ISO 4996, ISO 4951 | HS420D E420CC | ||||||
| GB/T 1591 – 2008 | Q420B | ASTM A572M, ASTM A633M | Gr.60, Gr.E | DIN EN 10113-2, DIN EN 10113-3 | S420NL, S420ML | JIS G3124 | SEV295, SEV345 | NF EN 10113-2, NF EN 10113-3 | S420NL, S420ML | BS EN 10113-2, BS EN 10113-3 | S420NL S420ML | ISO 4996, ISO 4951 | HS420D E420CC |
| GB/T 1591 – 2008 | Q420C | ASTM A678M, ASTM A656M | Gr.B, TyPe7 | DIN EN 10113-2, DIN EN 10113-3 | S420NL, S420ML | JIS G3124 | SEV295, SEV345 | NF EN 10113-2, NF EN 10113-3 | S420NL, S420ML | BS EN 10113-2, BS EN 10113-3 | S420NL S420ML | ISO 4996, ISO 4951 | HS420D E420CC |
| GB/T1591 – 2008 | Q420D | ASTM A678M, ASTM A656M | Gr.B, TyPe7 | DIN EN 10113-2, DIN EN 10113-3 | S420NL, S420ML | JIS G3124 | SEV295, SEV345 | NF EN 10113-2, NF EN 10113-3 | S420NL, S420ML | BS EN 10113-2, BS EN 10113-3 | S420NL S420ML | ||
| GB/T1591 – 2008 | Q420E | ASTM A678M, ASTM A656M | Gr.B, TyPe7 | DIN EN 10113-2, DIN EN 10113-3 | S420NL, S420ML | JIS G3124 | SEV295, SEV345 | NF EN 10113-2, NF EN 10113-3 | S420NL, S420ML | BS EN 10113-2, BS EN 10113-3 | S420NL S420ML | ||
