GB/T 8162 45# Seamless Carbon Steel Pipe
GB/T 8162 45# Seamless Carbon Steel Pipe for Automotive and Structural Engineering
Detailed material data for 45# seamless carbon steel pipe under GB/T 8162 standard, covering chemical composition, mechanical and thermal properties, international equivalents, and application guidance for structural and automotive components.
Hot rolling, cold drawing, normalizing, annealing, quenching and tempering, straightening, cutting
- Phone : +8618037372205
- Email : [email protected]
- WhatsApp: Contact via Whtsapp
- WeChat: +8618037372205
GB/T 8162 45# Seamless Carbon Steel Pipe Introduction
45# steel is a high-quality carbon structural steel widely used in China, specified in GB/T 8162 for seamless pipes in automotive and structural applications. With a medium carbon content (0.42–0.50%), it offers excellent strength and toughness after appropriate heat treatment, typical tensile strength exceeding 600 MPa and yield strength above 355 MPa. The grade is commonly supplied as hot-rolled or heat-treated seamless pipes, featuring good machinability, weldability, and surface quality. Its balanced mechanical properties make it ideal for manufacturing mechanical parts, drive shafts, hydraulic cylinders, and chassis components. International equivalents include ISO C45E4, JIS S45C, and ASTM 1045, ensuring global interchangeability. This data sheet provides comprehensive technical information for engineers and procurement professionals seeking reliable material specifications.
GB/T 8162 45# Seamless Carbon Steel Pipe Chemical Composition
Chemical composition of 45# steel shall conform to GB/T 699 (Quality carbon structural steels) as referenced by GB/T 8162. The limits ensure appropriate hardenability, strength, and machinability. Residual elements like Cr, Ni, and Cu are kept low to avoid adverse effects on weldability and toughness.
| Element | Standard Value (%) | Remarks |
|---|---|---|
| Carbon (C) | 0.42 – 0.50 | Primary strengthening element |
| Silicon (Si) | 0.17 – 0.37 | Deoxidizer; improves strength |
| Manganese (Mn) | 0.50 – 0.80 | Contributes to hardenability and tensile strength |
| Phosphorus (P) | ≤ 0.035 | Residual; considered impurity |
| Sulfur (S) | ≤ 0.035 | Residual; considered impurity |
| Chromium (Cr) | ≤ 0.25 | Residual element |
| Nickel (Ni) | ≤ 0.30 | Residual element |
| Copper (Cu) | ≤ 0.25 | Residual element; also from scrap |
GB/T 8162 45# Seamless Carbon Steel Pipe Thermal and Electrical Physical Properties
Physical properties are typical values for 45 steel (equivalent to AISI 1045) at ambient or specified temperatures. These data are derived from standard engineering references and are included for design calculations. Actual properties may vary slightly with heat treatment and product form.
| Property | Typical Value | Unit | Test Condition / Temperature |
|---|---|---|---|
| Density (ρ) | 7.85 | g/cm³ | 20 °C |
| Elastic Modulus (E) | 200 – 210 | GPa | 20 °C |
| Shear Modulus (G) | 80 | GPa | 20 °C |
| Poisson's Ratio (ν) | 0.30 | — | 20 °C |
| Thermal Expansion Coefficient (α) | 11.2 | 10⁻⁶/K | 20–100 °C |
| Thermal Expansion Coefficient (α) | 11.9 | 10⁻⁶/K | 20–200 °C |
| Thermal Expansion Coefficient (α) | 12.5 | 10⁻⁶/K | 20–300 °C |
| Thermal Expansion Coefficient (α) | 13.0 | 10⁻⁶/K | 20–400 °C |
| Thermal Expansion Coefficient (α) | 13.5 | 10⁻⁶/K | 20–500 °C |
| Thermal Conductivity (λ) | 50.2 | W/(m·K) | 20 °C |
| Thermal Conductivity (λ) | 48.1 | W/(m·K) | 100 °C |
| Thermal Conductivity (λ) | 44.4 | W/(m·K) | 200 °C |
| Thermal Conductivity (λ) | 37.7 | W/(m·K) | 400 °C |
| Specific Heat Capacity (c) | 486 | J/(kg·K) | 20 °C |
| Specific Heat Capacity (c) | 502 | J/(kg·K) | 100 °C |
| Specific Heat Capacity (c) | 519 | J/(kg·K) | 200 °C |
| Electrical Resistivity (ρe) | 0.15 – 0.20 | Ω·mm²/m | 20 °C |
GB/T 8162 45# Seamless Carbon Steel Pipe Mechanical Properties
Mechanical properties are based on GB/T 8162-2018 for seamless pipes in delivery condition (hot-rolled or normalized). Yield strength depends on wall thickness. Values are minimum requirements unless noted. Elongation is given for longitudinal and transverse test pieces according to standard procedures. Impact test and bending are not mandatory in the base specification but may be agreed upon.
| Property | Standard Requirement | Unit | Test Condition |
|---|---|---|---|
| Tensile Strength (Rm) | ≥ 600 | MPa | Room temperature, all wall thicknesses |
| Yield Strength (ReH) | ≥ 355 | MPa | Wall thickness ≤ 16 mm |
| Yield Strength (ReH) | ≥ 345 | MPa | Wall thickness > 16 – 30 mm |
| Yield Strength (ReH) | ≥ 335 | MPa | Wall thickness > 30 – 50 mm |
| Yield Strength (ReH) | ≥ 325 | MPa | Wall thickness > 50 – 100 mm |
| Elongation (A, longitudinal) | ≥ 16 | % | Gauge length 5.65√S0 (L0=50 mm for small specimens) |
| Elongation (A, transverse) | ≥ 14 | % | Transverse test piece, same gauge length |
GB/T 8162 45# Seamless Carbon Steel Pipe Exactly Equivalent Material Standards and Substitutable Grades
| Country/Region | Standard | Grade | Remarks |
|---|---|---|---|
| China | GB/T 699 | 45 | Base material standard for quality carbon structural steel |
| China | GB/T 8162 | 45 | Seamless pipe specific standard – the analysed product |
| International | ISO 683-1 | C45E4 | Heat-treatable carbon steel, identical chemistry |
| European Union | EN 10083-2 | C45E (1.1191) | Non-alloy steel for quenching and tempering |
| Japan | JIS G4051 | S45C | Carbon steel for machine structural use |
| United States | ASTM A29/A29M | 1045 | Hot-rolled carbon steel bars – chemistry matches |
| Germany | DIN 17200 | C45 | Historical German standard, predecessor of EN grade |
| Russia | GOST 1050 | 45 | Russian equivalent, similar chemical and mechanical properties |
GB/T 8162 45# Seamless Carbon Steel Pipe Application Introduction
45# seamless pipe is versatile for medium‑strength structural and mechanical components. Its good machinability and weldability (when preheated) allow it to be formed into a wide variety of parts. Typical applications span automotive frames, transmission shafts, hydraulic cylinders, agricultural machinery, and construction scaffolding. It is also used in bicycle tubing and general engineering where cost‑effective strength is required.
Product Applications: Seamless structural tubes for chassis and roll cages, Drive shafts and propeller shafts, Hydraulic cylinder barrels and piston rods, Boom and arm sections for agricultural equipment, Scaffolding tubes and couplers, Bicycle frame tubes (seat tubes, top tubes, down tubes)
Processed into products: Axle tubes and axle housings, Steering columns and tie rods, Bushings and sleeves, Bearing rings (after induction hardening), Connecting rods (after forging and heat treatment), Pin and pivot shafts
Application industries: Automotive manufacturing, Agricultural and earth-moving machinery, Hydraulic and pneumatic systems, Construction and scaffolding, Bicycle and motorcycle frames, General mechanical engineering
GB/T 8162 45# Seamless Carbon Steel Pipe Nearest Performance Similar Alternative Materials
| Country/Region | Standard | Grade | Remarks |
|---|---|---|---|
| China | GB/T 699 | 50 | Higher carbon (0.47–0.55%), slightly stronger but less ductile |
| China | GB/T 3077 | 40Mn | Added manganese (0.70–1.00%) for improved hardenability |
| United States | ASTM A29 | 1050 | Higher carbon equivalent to 50#; similar tensile but lower ductility |
| European Union | EN 10083-2 | C50E | Higher strength, less tough; good alternative if strength is priority |
| Japan | JIS G4051 | S50C | Similar to 50#, slightly higher strength |
Notes:
Ordering considerations: When ordering 45# seamless pipe to GB/T 8162, dimensions (outer diameter, wall thickness, length) and manufacturing method (hot‑rolled or cold‑drawn) must be clearly specified. The material can be supplied in normalized or quenched and tempered condition if improved mechanical properties are needed. For welded structures, preheating (150–300 °C) is recommended to avoid cold cracking. Surface quality and non‑destructive testing (e.g., ultrasonic inspection) can be agreed upon at the time of enquiry. Impact test requirements are not standard but can be added to the purchase order if required.
- Share
