Cold-rolled coils are produced by rolling hot-rolled coils below the recrystallization temperature. Since there is no heating in the production process, there are no defects such as pitting and iron oxide scale that often occur in hot rolling, and the surface quality is good and the finish is high. The dimensional accuracy of cold-rolled products is high, and the performance and structure of the products can meet some special requirements, such as electromagnetic properties, deep drawing properties, etc. Commonly used grades are: SPCC; SPCD; SPCE; ST12-15; DC01-06.
Hot-rolled coil has excellent properties such as high strength, good toughness, easy processing and good weldability, so it is widely used in shipbuilding, automobile, bridge, construction, machinery, pressure vessel and other manufacturing industries. Common materials are Q235B, Q345B, SPHC, 510L, Q345A, Q345E, etc.
Classification of hot rolled coils:
Hot-rolled coils can be divided into: straight hair coils and finishing coils (divided coils, flat coils, slit coils);
According to different materials and properties, it can be divided into: ordinary carbon structural steel, low alloy steel, alloy steel;
According to different uses, it can be divided into: cold forming steel, structural steel, automobile structural steel, corrosion-resistant structural steel, mechanical structural steel, welded gas cylinder and pressure vessel steel, pipeline steel, etc.
Corresponding grades and uses of different types of hot rolled coils:
Type | International Standard Number | Grade | Use |
Hot rolled mild steel | JIS G3131 | SPHC | Suitable for manufacturing cold-formed parts. |
SPHD |
SPHE |
DIN 1614（EN10111） | STW22(DD11) |
STW23(DD12) |
STW24(DD13) |
General structural steel | JIS G3101 | SS 330 | For general structural parts such as buildings, bridges, ships, vehicles, etc. |
SS 400 |
SS 490 |
SS 540 |
DIN 17100 (EN10025) | St 33(S185) |
St 37-2(S235JR) |
St 37-3(S235JO) |
St 44-2(S275JR) |
St 50-2(E295) |
St 52-3(S355JO) |
Welded structural steel | JIS G3106 | SM400A | Used for structural parts that require excellent welding performance such as buildings, bridges, ships, vehicles, oil tanks, construction machinery, etc. |
SM400B |
SM400C |
SM490A |
SM490B |
SM490C |
SM490YA |
SM490YB |
SM520B |
SM520C |
NSC | Welten590RE | Weldable high-strength steel plates for pressure vessels, oil tanks, construction machinery, mining machinery, pressure water pipes, etc. |
Steel for mechanical structures | DIN 17200 | C22 | For mechanical structural parts used after cutting and other processing and heat treatment. |
JIS G4501 | C35 |
—— | S20C |
Fine grain structural steel | DIN 17102 | StE255 | Fine grain structural steel suitable for welding. |
StE355 |
Steel strip for steel pipe | JIS G3132 | SPHT1 | For welded steel pipes. |
SPHT2 |
SPHT3 |
Steel for automobile structure | JIS G3113 | SAPH 310 | Used for automotive structural parts such as automotive frames and wheels that require formability and processability. |
SAPH 370 |
SAPH 400 |
SAPH 440 |
SEW 092 (EN10149-2) | QStE 340TM（---） | Hot-rolled pellet steel for cold deformation, used for structural parts such as automobile girders that require good cold forming properties and have high or high strength requirements. |
QStE 380TM（---） |
QStE 420TM（S420MC） |
QStE 380TM（S460MC） |
QStE 500TM（S500MC） |
Steel for boilers and pressure vessels | DIN 17155 (EN10028-2) | HII (P265GH) | In addition to guaranteeing normal temperature performance, it also guarantees mechanical properties at higher temperatures, suitable for steam boiler equipment, pressure vessels with higher working temperature and similar structural parts. |
19Mn6(P355GH) |
JIS G3103 | SB410 |
JIS G3116 | SG295 | Welded steel plates for gas cylinders. |
SG325 |
Steel for hull structure | LR,BV | A | Available according to national specifications. |
GL,DNV | B |
ABS | D |
Atmospheric corrosion resistant steel | SEW087 (EN10155) | WTSt37-2(S235J2W) | It is used to manufacture structural parts that require resistance to atmospheric corrosion, such as containers, railway vehicles, oil derricks, and construction machinery. |
WTSt52-3(S355J2G1W) |
NSC | NAW 400 |
NAW 490 |
Sulfuric acid corrosion resistant steel | S-ten2 | Containers for the manufacture of hydrogen sulfide-containing media, etc. |
Seawater corrosion resistant steel | Mariloy G41A | Used for structural parts such as oil production platforms, ships, seaport buildings, etc. |
Mariloy S50A |
Case hardened steel | DIN 17210 | C10 | High-purity low-carbon steel is used for surface carburizing or nitriding and then quenching and hardening to manufacture structural parts with high hardness on the surface, wear resistance and high toughness in the core. |
C15 |
JIS G4051 | S09CK |
S15CK |
High toughness pipeline steel | API 5L | X60 | For the production of spiral welded pipes, high toughness pipeline steel for oil pipelines, hot-rolled wide-band steel. |
X70 |
Steel for straight seam welded casing | API 5CT | J55 | For manufacturing straight seam welded oil casing. |
Hot rolled coil for pipeline | API 5L | Grade A,B | Oil and gas pipelines. |
X42,X46,X52 |
A56,X60,X65 |
X70 |
