Q235 Q195 Q345 Carbon Steel Coil

Product Description

Production Process

Cold rolled coil production process:

Hot coil - pickling - cold rolling - annealing - flattening - finishing (slitting, cross-cutting, coiling, etc.) - finished product delivery.

Cold rolled sheet production process:

Hot rolled coil (raw material) - pickling - cold rolling - degreasing - annealing - smoothing - shearing - finished product delivery
Commonly used national standard numbers for cold-rolled coils:

National standard number 

of cold rolled coil

ClassificationExplain
JISG3141-2005SPCCRepresents cold rolled steel strip for general use
SPCDFor stamping
SPCEFor deep drawing
SPCFFor special deep drawing
SPCGFor super deep drawing
EN10130/EN10139DC01Represents cold rolled steel strip for general use
DC03For stamping
DC04For deep drawing
DC05For special deep drawing
DC06For super deep drawing

BQB402-2005

(Cold rolled carbon steel plate and strip)

SPCCRepresents cold rolled steel strip for general use
SPCDFor stamping
SPCE/SPCENFor deep drawing

BQB403-2005

(Cold rolled low carbon steel sheet and strip)

DC01Represents cold rolled steel strip for general use
DC03For stamping
DC04For deep drawing
DC05For special deep drawing
DC06For super deep drawing
SAE1008/1010----

Common grades of cold rolled coils: Q195A-Q235A, Q195AF-Q235AF, Q295A(B)-Q345 A(B); SPCC, SPCD, SPCE, ST12-15; DC01-061

1. Chemical Composition (Mass Percentage)

The main components of carbon steel coils are iron (Fe) and carbon (C), with other element contents adjusted based on grade and application requirements. Typical chemical compositions are as follows:



Element Typical Range Remarks



Carbon (C) 0.06%~0.35% Low-carbon steel (e.g., SPHC, Q195): typically ≤0.15%; Medium-carbon steel (e.g., Q235): ≤0.22%; High-carbon steel (e.g., 65Mn): up to 0.60%~0.90%.

Manganese (Mn) 0.30%~1.50% Enhances strength and hardenability. For example, SPHC: Mn ≤0.50%; Q345B: Mn 1.00%~1.60%.

Silicon (Si) ≤0.35% Acts as a deoxidizer and improves strength. Some grades allow trace additions (e.g., SPHC: Si ≤0.10%).

Sulfur (S) ≤0.035%~0.050% Excessive sulfur causes hot brittleness and must be strictly controlled (e.g., API 5L PSL2 requires S ≤0.015%).

Phosphorus (P) ≤0.035%~0.050% Excessive phosphorus reduces toughness. High-demand applications (e.g., low-temperature steel) require P ≤0.025%.

Other Elements Trace (e.g., Cu ≤0.40%, Cr ≤0.30%) Residual elements typically total ≤0.70% (e.g., EN 10111 standard).

Example Grades:

SPHC (JIS Standard): C ≤0.15%, Mn ≤0.50%, S ≤0.035%, P ≤0.035% (cold-rolled low-carbon steel coil).

Q235B (GB/T 700): C ≤0.20%, Mn ≤1.40%, S ≤0.045%, P ≤0.045% (general structural steel coil).

ASTM A36: C ≤0.26%, Mn ≥0.80%, S ≤0.050%, P ≤0.040% (hot-rolled coil for construction).



2. Mechanical Properties

The mechanical properties of carbon steel coils depend on composition, rolling process (hot-rolled/cold-rolled), and heat treatment. Typical properties include:

2.1 Basic Mechanical Properties



Property Typical Range Example (Hot-Rolled Coil) Example (Cold-Rolled Coil)



Tensile Strength (σ₆) 270~650 MPa Q235B: 370~500 MPa SPCC: 270~410 MPa

Yield Strength (σₛ) 170~450 MPa Q345B: ≥345 MPa (thickness ≤16mm) SPHC: ≥170 MPa

Elongation (δ₅) 15%~40% Q235B: ≥26% (thickness ≤40mm) SPCC: ≥32% (50mm gauge length)

Hardness (HB/HRB) 70~200 HB / Hot-rolled coils have higher hardness (e.g., Q345B: 120~160 HB); Cold-rolled coils have lower hardness (e.g., SPCC: ≤65 HRB).
50~90 HRB

2.2 Additional Performance Requirements

Bending Performance: Cold-rolled coils must pass a 180° bending test without cracking (e.g., SPCC).

Impact Toughness: Low-temperature steel coils (e.g., Q345D) require impact energy ≥34 J at -20°C (V-notch).

Surface Quality: Cold-rolled coils demand high surface smoothness (e.g., automotive panels must be free of scratches and oxide layers).

Chemical composition of cold rolled coil
BrandCMnPSAlta
DC01, SPCC≤0.12≤0.60≤0.045≤0.045≥0.020
DC02, SPCD≤0.10≤0.45≤0.035≤0.035≥0.020
DC03, SPCE≤0.08≤0.40≤0.030≤0.030≥0.020
DC04, SPCF≤0.06≤0.35≤0.025≤0.025≥0.015
 
Characteristics of cold rolled steel coils
➤ Material① Carbon steel (different grades such as CQ, DQ, DDQ, EDDQ, etc.)
② Alloy steel (HSLA, high-strength steel, ultra-high-strength steel, etc.)
There are many materials of cold-rolled sheet, but its classification can basically be classified into two categories: carbon steel and alloy steel according to the two major characteristics of chemical composition and mechanical properties. 
➤ Features
① Good surface quality and good stamping performance, so it can be widely used in the automotive industry, food cans, aerospace, precision instruments and many other fields.
② With good heat resistance, the cold-rolled sheet processed by the rolling process is generally more heat-resistant than the ordinary sheet.
③ It has good heat reflectivity. Cold-rolled steel processed by processing technology under normal temperature crystallization has stable surface properties, and can emit heat well under the condition of heating to protect the plate.

Cold-rolled coil uses and models
Product NameGradeStandardUse
Carbon structural steel cold rolled sheet (coil) and strip

Q195 Q235-A

 SPCC ST12

GB11253-89 JISG3141 DIN1623Used in automobile manufacturing, machinery manufacturing, light industry, civil and construction industries
High quality carbon structure cold rolled sheet (coil) and strip

08AI, Z, S,

 P SPCD ST14

GB710-88 JSG3141 DIN1623For automobile manufacturing, tractor, light industry ordinary stamping and forming parts
Cold rolled sheet and strip for deep drawing

08AI ZF, HF,

 F SPCE ST14

GB5213-85 JISG3141 DIN 1623For the manufacture of automobiles and tractors, forming complex stampings

Cold rolled 

steel sheet and strip for bicycles

ZQ195 ZQ21

5 Z06AI

GB3644-89Steel plates and belts for bicycles

Continuous 

hot-dip galvanized sheet (coil)

Deep-drawing grad

e SC; Super deep-drawing grade CS; Ordinary grade mechanical bite grade JY

GB2518-88For drawing and complex shaped parts, for deep drawing and more complex shaped parts, for simple forming and hand processing, thickness < 1.5mm for mechanical engagement, thickness < 0.9mm For roll-over bite and general forming
Continuous electroplating tin sheet (coil)MR, DGB2520-2000Used in food can making, chemical and medical packaging, textile and electronic industrial parts, etc.
Color coated steel sheet (coil)DL, DP, XTGB/T12754-91Box structure and interior and exterior decoration for construction, transportation, furniture, home appliances, and electronics industries
Cold rolled sheet and strip for 200 liter steel drumsLTXY1 XT2YB/T055-94Dedicated to the manufacture of 200 liter steel drums
Cold-rolled steel sheet and strip for automobile trunksQG40Q/WG (LA) 14-88Suitable for making car trunks
Cold-rolled steel sheet (coil) for atmospheric corrosion resistance

05CuPCrNi

 06CuPRE

WGJS21-2001Used for automobile railway vehicles and marine containers, etc.; steel for automobiles, railway manufacturing and marine containers
Structural steel cold rolled sheet and strip for marine containersJ335Q/WG (LZ) 17-92Steel for marine containers and other industrial structures
Cold rolled sheet steel for double coil welded pipeWBDW/WG (LZ) 18-95Refrigerator, automobile manufacturing and other industries double-layer
Semi-process cold rolled non-oriented electrical steel stripBDGQWG (LZ) 19-96Used in the manufacture of compressor motor cores
Polyvinyl chloride template plate and steel stripQG40Q/WG (TC) 01-94Substrate for polyvinyl chloride mold
Steel belt for color coatingQG40Q/WG (LZ) 11-93Substrate for color coating
Shadow mask frame steel belt

WYK-

2 WYK-1

Q/WG (LZ) 11-98Color TV Frame Substrate
 
What is cold rolled sheet steel?
Cold rolled sheet is a product obtained by cold pressing (cold rolling) of hot rolled sheet. The thickness of the steel plate is not more than 4mm, and the width is not less than 600mm.
The surface quality of cold-rolled sheet is better than that of hot-rolled sheet due to repeated cold rolling. After heat treatment, good mechanical properties can be obtained.
Cold-rolled sheets are mainly used in household appliances, automobiles, agricultural machinery and other manufacturing industries, as well as as raw materials for galvanized sheets, tin-plated substrates and thin-walled welded pipes. In recent years, the application scope of stainless steel cold-rolled sheet in my country has been expanding. In addition to corrosion-resistant containers and mechanical parts used in aviation, petrochemical, food, medical equipment and other industries, it is also used in the shell of household appliances, the decoration of hotels, restaurants, etc. Kitchen utensils, household utensils, etc. have also been widely used.

According to the type of steel used and the purpose of the product, the cold-rolled sheet is divided into the following categories:
➤ Carbon structural steel and low alloy structural steel cold rolled sheet (GB/T11253-89)
➤ High-quality carbon structural steel cold-rolled sheet (GB/T13237-91)
➤ Alloy structural steel cold rolled sheet (YB/T5132-93)
➤ Stainless steel cold rolled sheet (GB3280-92)
➤ Cold-rolled sheet steel for deep drawing (GB5213-85)
➤ Cold-rolled steel sheet for daily enamel (GB/T13790-92)
➤ Cold rolled sheet steel for 200 liter steel drums (YB/T055-94)
➤ Cold-rolled sheet steel for welding gas cylinders (GB6653-94)

According to the requirements for the use of cold-rolled sheets in household appliances (refrigerators, washing machines) and automobile manufacturing, cold-rolled sheets are usually divided into general cold-rolled sheets, stamping-grade cold-rolled sheets, deep-drawing, extra-deep-drawing and ultra-deep-drawing cold-rolled sheets. Rolled sheet, the grades of steel are Q195, Q215, Q235, 08Al, SPCC, St12, St13, St14, etc.

Epilogue
Bao Steel focuses on the production of carbon steel products, providing you with high-quality cold-rolled sheets, cold-rolled coils and other carbon steel products and high-quality services, and looking forward to becoming a forever partner with you! We have experienced technicians and a complete production line, which can provide services such as cutting and product customization. Welcome to communicate with us!


Product Show

Company Profile

BAOSTEEL Co., Ltd is a comprehensive company, who is founded in 2008. Specialized in Carbon steel, alloy steel, galvanized steel in pipe and tube,plate and coil,profiles.

We are located in Tianjin Province, the Steel base of China, It is well-known all over the world. We are close to Tianjin Seaport, that is much convenient in carriage.

We welcome all users, manufacturers and traders to cooperate with us

Since our establishment, we have always adhered to the business policy of "Quality for Survival, Product for Development, Credibility for Cooperation and Service for Customer". Under the guidance of this business policy, our company acts as a perennial distributor of steel pipe, steel plate, steel coil, steel rod, steel profiles of Angang Steel, HBIS, JISCO,SGHB ,and etc.

Modern large-scale outdoor storage and indoor storage have been set up in our company, and 20,000 tons of available goods have been prepared.

Factory Show

Service

Pre-sale Service

1.We provide samples free of charge, but the freight should be paid by the buyer.
2. We have full stock,and can deliver within short time.Many styles for your choices. 
3. OEM and ODM order are accepted, Any kind of logo printing or design are available.
4. Good Quality + Factory Price + Quick Response + Reliable Service, is what we are trying best to offer you.
5. All of our products are produce by our professional workman and we have our high-work-effect
foreign trade team, you can totally believe our service. 

After you choose

1. We will count cheapest shipping cost and make invoice to you at once.
2. Check quality again, then send out to you at 1-2 working day after your payment,
3. Email you the tracking no, and help to chase the parcels until it arrive you.

After-sale choose

1. We are very glad that customer give us some suggestion for price and products.
2. If any question,please contact with us freely by E-mail or Telephone.

FAQ

Q1:Can you send samples?
A:Of course, we can provide customers with free samples and express shipping service to all over of the world.

Q2:What product information do I need to provide?
A:Please kindly provide the grade, width, thickness, surface treatment requirement should you have and quantities you need to purchase. 

Q3:It's my first time to import steel products, can you help me with it?
A:Sure,we have agent to arrange the shipment, we will do it together with you.

Q4:What ports of shipment are there?
A:Under normal circumstances, we ship from Shanghai, Tianjin, Qingdao, Ningbo ports, you can specify other ports according to your needs. 

Q5:What about product prices information?
A:Prices various according to periodic price changes of raw materials. 

Q6:What is your terms of payment ?
A:Payment<=1000USD, 100% in advance. Payment>=1000USD, 30% T/T in advance ,balance before shipment or based on BL copy or LC at sight.

Q7.Do you provide custom made Products service?
A: Yes,if you have your own design , we can produce according to your specification and drawing.

Q8:What are the certifications for your products?
A:We have ISO 9001, MTC, third parties’ inspections are all available such SGS, BV ect.

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