Trunnion Ring for Basic Oxygen Furnace

Product Specifications

Technical details and manufacturing context for Trunnion Ring

Definition

The trunnion ring is a critical load-bearing component of a Basic Oxygen Furnace (BOF) vessel assembly. It is a large, robust ring structure mounted to the vessel shell that interfaces with the trunnion pins or bearings on the furnace tilting mechanism. Its primary function is to transfer the immense weight of the vessel (including its refractory lining and molten metal charge) to the supporting structure while allowing the vessel to be tilted for charging, refining, and tapping operations. The ring is typically made of forged or cast alloy steel, with material grades such as ZG270-500 per GB/T 11352, offering tensile strength of 500–650 MPa and yield strength of 270–350 MPa. Key dimensions include bore diameter of 1500–3000 mm, outer diameter of 2000–4000 mm, thickness of 200–500 mm, and weight of 5000–20000 kg. Machining tolerance is ±0.05 mm (ISO 2768-m), surface roughness Ra 1.6–3.2 μm (ISO 1302), and operating temperature range -20 to 300°C. Non-destructive testing is 100% ultrasonic per GB/T 7233.1. The ring must withstand high static loads, dynamic stresses during tilting, and thermal stresses from the hot vessel. It is essential for the safe and efficient operation of the BOF, and its design and manufacturing require strict adherence to standards. Always verify model-specific values and standards with the legal manufacturer or supplier.

Working Principle

The trunnion ring is rigidly attached to the BOF vessel shell. It rotates on fixed trunnion pins or within large bearings that are part of the stationary furnace support structure. Hydraulic or electric drives apply torque to the ring (often via a gear attached to it), causing the entire vessel to tilt around its horizontal axis. The ring must withstand high static loads, dynamic stresses during tilting, and thermal stresses from the hot vessel. Its design ensures that the vessel can be tilted for charging, refining, and tapping operations while maintaining structural integrity.

Common Materials

Forged or Cast Alloy Steel

Technical Parameters

Parameter	Typical range	Notes & selection driver
Bore Diameter	1500–3000 mm	Matches BOF vessel trunnion shaft size
Outer Diameter	2000–4000 mm	Determines bearing and housing interface
Thickness	200–500 mm	Provides structural rigidity
Weight	5000–20000 kg	Affects handling and installation
Material Grade	ZG270-500	Cast steel with high strength and toughnessGB/T 11352
Tensile Strength	500–650 MPa	Minimum 500 MPa for structural integrityGB/T 11352
Yield Strength	270–350 MPa	Ensures elastic deformation under loadGB/T 11352
Hardness	150–200 HBW	Balances wear resistance and machinabilityGB/T 231.1
Machining Tolerance	±0.05 mm	Critical for bearing fitISO 2768-m
Surface Roughness	Ra 1.6–3.2 μm	Sealing and fatigue lifeISO 1302
Operating Temperature	-20–300 °C	Thermal expansion considered
Non-Destructive Testing	100% UT	Ultrasonic testing for internal defectsGB/T 7233.1

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Components / BOM

Ring Body Part
The main structural element, designed to handle bending moments and compressive loads.

Material: Forged or Cast Alloy Steel
Mounting Flange Part
The interface surface with bolt holes for attaching the ring to the BOF vessel shell.

Material: Alloy Steel
Gear Teeth Segment (if applicable) Optional Part
Machined teeth on the ring's outer circumference to engage with the drive pinion for tilting.

Material: Hardened Alloy Steel
Bearing Surface Part
The machined surface that contacts the trunnion pins or bearing pads, allowing rotation.

Material: Hardened Alloy Steel

Applied To / Applications

This component is essential for the following industrial systems and equipment:

Basic Oxygen Furnace Vessel

View system integration details

Manufacturers of Trunnion Ring

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Frequently Asked Questions

What is the primary function of a trunnion ring?

The trunnion ring transfers the weight of the BOF vessel to the support structure while allowing tilting for charging, refining, and tapping.

What materials are commonly used for trunnion rings?

Forged or cast alloy steel, with grades like ZG270-500 per GB/T 11352, providing high strength and toughness.

What are typical dimensions of a trunnion ring?

Bore diameter 1500–3000 mm, outer diameter 2000–4000 mm, thickness 200–500 mm, and weight 5000–20000 kg, but these must be confirmed for specific applications.

What standards apply to trunnion ring manufacturing?

Material and testing standards include GB/T 11352, GB/T 231.1, ISO 2768-m, ISO 1302, and GB/T 7233.1. Always verify compliance with the manufacturer.

Data Basis

Editorial classification, named public sources where available, and source-reviewed manufacturer records.

Preliminary Technical Classification

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pressure:	Atmospheric to 0.5 bar (7.25 psi) differential pressure
other spec:	Max vessel weight: 300-500 metric tons, Rotation speed: 0.1-1.0 RPM, Slurry concentration: N/A (structural component)
temperature:	Ambient to 400°C (752°F) continuous, 500°C (932°F) peak

Trunnion Ring

Product Specifications

Applied To / Applications

Industrial Ecosystem & Supply Chain Structure

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