How to make strong welded H-beam connections?

Want stronger welded H-beam connections? In this article we explain need to know welding terms useful for weld preparation for H-beams.

For more h beam manufacturing lineinformation, please contact us. We will provide professional answers.

 

Welding Terminology

There is often much confusion in beam welding terminology. Below are some of these terms explained.

Intersection geometry

Skew

Acute angle between member axes in the horizontal plane.

Slope

Acute angle between member axes in a vertical plane. Also called &#;inclination&#;.

Shape

Actual geometry to create the end cut, cut-out or hole for a proper fit.

 

Weld Preparation

Groove angle φ

The angle between opposing faces of the connected parts which create a groove to be filled up with weld materials. Can be an inside or outside groove angle for weld preparation.

Bevel angle β

The angle formed between a centerline perpendicular to the wall and the cut face of the wall. Equal to cutting angle and can be negative or positive.

• A perpendicular cut has β=0°;
• Largest β plasma 45° (- or +).

Dihedral angle ψ

Angle between the outer faces of the connected walls. Calculations for optimal weld preparation are based on ψ.

Root opening (R)

The separation at the joint between the walls after fitting. Technique to increase the joint penetration for stronger connections.

Rathole

An opening in the web right under the flange to achieve complete flange joint penetration and allow nondestructive tests. Read more about ratholes below

Weld types

• Fillet weld
• Groove weld
• Butt weld

 

Guide to weld preparation for welded H-beam connections

HGG develops beam cutting machines to cut copes and weld preparation with a wide variety of bevel types.

Bevel cutting

None

Preferred in case of bolted connections or to apply fillet welds.

Single groove

Bevel cut for groove weld. Weld preparation on top side or bottom side.

Single groove with nose

Bevel cut for groove weld with broad root face. Weld preparation on top side or bottom side.

Double groove

X-bevel cut for X or K groove welds. Small root face can be applied after cutting.

Double groove with nose

X-bevel cut for X or K groove welds with broad root face.

 

Ratholes

This open hole in the web right up against the flange allows continuous weld passes on flange joints across the web with complete joint penetration. The necessary reduction in the web brings avoidance of defects like discontinuities, inclusions and incomplete penetration of the passes. Ratholes enable nondestructive testing of the full joint. Depending on the contract documents and included welding regulations a fabricator can choose not to apply ratholes. This avoids reduction of the web but possible defects that cannot be tested need to be taken into account during strength calculation.

None
No reduction in web section for full strength. Nondestructive tests of welds located across the web are not possible.

 

Type 1
Traditional rathole. The required torch to flange distance for web cuts requires a minimum of grinding.

  

Type 6
HGG optimised rathole. No grinding required.

 

AWS 6.2
Weld inspection hole for seismic moment connections (CAD-CAM only).

 

A practical example

The examples below help you to understand the structure of this document. Cuts are available for end shapes, holes and cut-outs. Four cuts are needed to define a beam end shape. Top flange, top web, bottom web and bottom flange. The weld preparation is shown on the right side of the cut.

 

See more examples in the article &#;The 7 Most Used Beam Connections Explained&#;.

 

Find out more about welded H-beam connections

Do you want to know more about making strong welded H-beam connections?

• Download the full article &#;Unlimited work preparation of beams and bars&#;

 

H steel beams are made in the production and processing area, and welded H-shaped steel beams are made uniformly in the h steel beams factory and exporter. The steel beam production process is as follows:

are made in the production and processing area, and welded H-shaped steel beams are made uniformly in the. The steel beam production process is as follows:

Raw material correction

&#;

setting out

&#;

numbering

&#;

blanking

&#;

parts processing and welding

&#;

sandblasting and rust removal

&#;

painting.

1. Staking out and cutting materials

Accurately calculate the cutting length of the steel beam based on the measured and reviewed frame column and beam axes. Cut the material to ensure the cut is flat and vertical. When the section steel needs to be extended, the 45° connection method is used, and the flange plate and web joints are staggered. When setting out, the welding shrinkage allowance during production and installation and the processing allowance for cutting, planing and other processing should be reserved according to the process requirements. The allowable deviation for setting out shall comply with the provisions of Table 1.

Table 1

Item

 

Allowable Deviation

Parallel Line Distance and Segment Size

±0.5

Diagonal Difference

1.0

Width, Length

±0.5

Hole Spacing

±0.5

Angle of Processed Template

±20

 

Before cutting, the surface of the steel cutting area should be cleaned of rust, dirt, etc. When cutting and blanking, the workpiece should be placed on a special flat bracket to ensure that the workpiece does not tilt or shake and reduce blanking errors. The allowable deviation of cutting shall comply with the provisions of Table 2 and the quality of the cutting surface shall comply with the provisions.

Table 2

Want more information on Pipe Rotator? Feel free to contact us.

Item

Allowable Deviation (mm)

Component Width, Length

±3.0

Surface Flatness of the Cutting Process

0.05t but not greater than 2.0

Scoring Depth

0.2

Local Notch Depth

1.0

 

2. Steel beam assembly and welding

Before assembling the H-shaped steel beam, check whether the web and flange plates need to be corrected. Only when they are qualified can assembly and welding be carried out. Welding mainly uses (semi-)automatic welding machines, combined with manual arc welding. Before welding, the welder should review the joint quality of the weldment and the treatment of the welding area. If it does not meet the requirements, it should be repaired and qualified before welding. Do not use damp flux or rusty welding wire.

When welding long welds, use the reverse reverse welding method or the layered reverse reverse welding method. During manual arc welding, multiple welders are used to weld symmetrically at the same time to eliminate welding deformation as much as possible. At the same time, short arc welding is used to prevent air from intruding into the welding area and causing cracks and pores in the weld metal.

After welding is completed, the welder should clean the slag on the surface of the weld and check the appearance quality of the weld. The outer dimensions of the weld should comply with the current national standard "Outline Dimensions of Steel Structure Welds". The T-shaped connection welds between the upper and lower flange plates and the web of the H-shaped steel beam should be fully welded, and its appearance inspection and non-destructive inspection should comply with its design requirements and relevant quality standards.

In order to prevent or reduce welding deformation, welding should be carried out strictly according to the established welding process. After welding, the welded H-shaped steel should be placed on the section steel straightening machine for correction. The allowable deviation of welded H-shaped steel should comply with the provisions of Table 3.

Table 3

Project

Permissible Deviation (mm)

Component Width, Length

±3.0

Surface Flatness of Cut Face

0.05t and not greater than 2.0

Scoring Depth

0.2

Local Notch Depth

1.0

 

3. Steel beam rust removal and coating

The surface of the components will be rust-removed and painted. Only the rust will be removed within 100mm from the on-site welding seam. No painting will be done for the time being. After the on-site welding is completed, re-painting will be carried out according to the original painting requirements.

3.1 Rust removal

The steel structure uses sandblasting to remove rust and complies with the relevant regulations. The relative humidity of the construction environment should not be greater than 85%. The workpiece after derusting must be polished with a grinding wheel to remove all welding nodules, spatter, and the hardened layer of the flame correction area on the surface of the workpiece before proceeding to the next process. Rust needs to be removed again.

3.2 Application

After the rust removal of the steel is inspected and passed, the first primer should be applied to the surface. Generally, the primer should be applied within 24 hours after the rust removal is completed. The paint should be used in accordance with the design requirements. After the first coat of primer is dry, the intermediate paint and topcoat should be applied to ensure that the coating thickness meets the design requirements. The paint should be applied evenly and not smear during application.

(1)Construction preparation

Choose paint according to the requirements of the design drawings.

Prepare rust removal machinery and painting tools.

Before painting, the steel structure and components have been inspected and accepted and meet the design requirements.

(2)Coating construction

Base surface cleaning: Before brushing, clean away rust, weld coating, welding spatter, oil, dust and other debris in the parts to be painted.

Blend the paint, control the viscosity, consistency, and dilution of the paint, and stir thoroughly when mixing to make the paint color and viscosity uniform.

When applying the first coat of paint, the painting direction should be consistent and the paint should be applied neatly.

After the first coat is dry, apply the second coat. The direction of the second coat of paint should be perpendicular to the direction of the first coat. This will make the thickness of the paint film uniform.

After painting, mark the components according to their original numbers: major components also need to be marked with weight, center of gravity position and positioning number.

(3)Coating inspection and acceptance

During and after surface coating construction, the painted workpieces should be protected from flying dust and other debris. After-painting inspection, the coating should be consistent in color, bright in color, bright, wrinkle-free, and pimple-free.

Are you interested in learning more about Pipe Rotator For Welding? Contact us today to secure an expert consultation!