# How Laser Power Affects Welding: Explained

Read this article with the following questions: 1. Principle of double beam welding Classification of laser welding 1) According to power density and weld formation characteristics: 2) According to the laser output mode: Fig. 1 Schematic diagram of pulsed laser welding and continuous laser welding 2. Selection of laser power P The choice of P […]

• What is the weld forming factor? How to calculate?
• What is the basis for selecting laser output power during laser welding?
• What are the effect of decreasing laser output power on weld penetration and achievable welding speed?

## 1. Principle of double beam welding

### Classification of laser welding

1) According to power density and weld formation characteristics:

• Heat conduction welding: power density (laser output power / focal spot area) ＜ 105W/cm2
• Deep penetration welding: power density > 106W/cm2

2) According to the laser output mode:

• Pulse laser welding
• Continuous laser welding

Fig. 1 Schematic diagram of pulsed laser welding and continuous laser welding

## 2. Selection of laser power P

The choice of P (laser power) is based on the thickness of the plate. P determines the power density of the spot and influences both the penetration depth and the welding speed.

Fig.2 Curve of power density and metal temperature with time

## 3. Effect of laser power on penetration

As illustrated in the figure, the greater the power (P/kw), the deeper the penetration, and vice versa.

Fig. 3 Relationship between laser penetration and power

## 4. Influence of laser power on welding speed

Supplementary knowledge points:

The form factor of a weld is defined in GB/T3375-1994 as the ratio of the weld width (B) to the calculated weld thickness (H) on the cross-section of a single weld (φ = B/H), as shown in Figure 4.

A small form factor results in a narrow and deep weld. However, the center of the weld tends to have higher concentrations of impurities and poor thermal crack resistance due to regional segregation. Therefore, the form factor should not be too small.

For example, the form factor of the weld should be greater than 1.3, meaning the width of the weld should be at least 1.3 times the calculated thickness of the weld.

Fig. 4 Laser power and speed determine the forming of weld

Fig. 5 Relationship between welding speed and laser power

## 5. Relationship between laser power, welding speed and penetration

Fig. 6 Changes of penetration and welding speed of low carbon steel under different power

## Summary:

The laser welding power determines the power density of the spot and controls the penetration depth and speed of welding. As the laser power increases, both the welding speed and penetration depth increase.

Don't forget, sharing is caring! : )
Author

#### Shane

##### Founder of MachineMFG

As the founder of MachineMFG, I have dedicated over a decade of my career to the metalworking industry. My extensive experience has allowed me to become an expert in the fields of sheet metal fabrication, machining, mechanical engineering, and machine tools for metals. I am constantly thinking, reading, and writing about these subjects, constantly striving to stay at the forefront of my field. Let my knowledge and expertise be an asset to your business.

#### Punching Force Calculator & Formula (Online & Free)

Have you ever wondered how to ensure a successful metal stamping project? In this blog post, we'll dive into the critical factors that can make or break your stamping process.…

#### Sheet Metal Gauge Thickness Chart (Steel, Aluminum, Brass)

Have you ever wondered what those numbers on sheet metal mean? In this article, we'll dive into the world of sheet metal gauge and demystify this essential aspect of metalworking.…

#### Electric vs Hydraulic Press Brake – Which One is Right for Your Business?

I. Introduction With the increasing development of technology, modern sheet metal processing, especially the bending process, requires higher and higher standards. There are different technical requirements for equipment and processing…

#### Laser Cutting Thickness and Speed Chart (500W-30kW)

Curious about the capabilities of laser cutting? In this comprehensive guide, we'll dive into the world of laser cutting speeds and thicknesses for various metals. Our expert mechanical engineer will…

#### Z Purlin Weight Calculator & Chart (Online & Free)

Have you ever wondered about the hidden world of Z-purlins? In this captivating article, our expert mechanical engineer will guide you through the intricacies of calculating Z-purlin weight. Discover how…

#### H Beam Sizes and Weight Chart

Have you ever wondered about the hidden world of H-beam steel? In this captivating article, we'll unravel the mysteries behind these essential construction components. Our expert mechanical engineer will guide…

#### Chequered Plate Weight Calculator (Online & Free)

Have you ever wondered about the weight of those patterned steel plates you see every day? In this blog post, we'll dive into the fascinating world of checkered steel plates.…

#### K Factor Calculator for Sheet Metal Bending (Online & FREE)

Are you struggling to design accurate sheet metal parts? Unlock the secrets of the K-factor, a crucial concept in sheet metal fabrication. In this article, our expert mechanical engineer demystifies…

#### I Beam Weight Chart, Sizes & Online Calculator

Have you ever wondered how to select the perfect I-beam for your construction or manufacturing project? In this blog post, our expert mechanical engineer will guide you through the process…

#### Copper vs. Aluminum Cables: A Comprehensive Comparison

I. Advantages of Copper Core Cables over Aluminum Core Cables: 1. Low resistivity: The resistivity of aluminum core cables is about 1.68 times higher than that of copper core cables.…

#### How to Choose the Right Safety Valve: A Step-by-Step Guide

Due to the diversity of safety valves and the diversity and complexity of pressure systems, when selecting a safety valve, the impact of factors such as temperature, pressure, and medium…

#### Safety Valve Usage Tips: Enhance Your System’s Security

The researcher conducted a project on a hotel’s hot water system, which provides full-time supply with steam (0.3Mpa) as the heat source, water supply temperature of 60-55 degrees, using a…