Fusion zone microstructure and geometry in complete-joint-penetration laser-arc hybrid welding of low-alloy steel

H. L. Wei, J. J. Blecher, Todd Palmer, Tarasankar Debroy

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

The fusion zone geometry and microstructure in complete-joint-penetration hybrid laser gas metal arc welds of a low-alloy steel are examined experimentally and theoretically. Weld geometry and spatially variable cooling rates are investigated using a three-dimensional heat transfer and fluid flow model. Experimentally measured microstructures are compared with those estimated from a microstructure model based on kinetics and thermodynamics of phase transformations, for a range of laser arc separation distances and heat inputs. Considerable variations in both cooling rates and microstructure were observed for the range of process parameters utilized. In fact, the experimental results and calculations show that for the same heat input, a predominantly ferritic and predominantly martensitic microstructure can be obtained, depending on the laser arc separation distance and resulting cooling rate. A process map is constructed showing the effect of welding speed, laser power, and laser arc separation distance on cooling rates and microconstituent volume fractions. The map indicates a martensite-free microstructure can be maintained over a wide range of welding parameters.

Original languageEnglish (US)
Pages (from-to)135s-144s
JournalWelding Journal
Volume94
Issue number4
StatePublished - Apr 1 2015

Fingerprint

High strength steel
Welding
Fusion reactions
Microstructure
Geometry
Lasers
Cooling
Welds
Gas lasers
Martensite
Flow of fluids
Volume fraction
Phase transitions
Thermodynamics
Heat transfer
Kinetics

All Science Journal Classification (ASJC) codes

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys

Cite this

@article{9300fdd271eb47e49c31e47ad23288b4,
title = "Fusion zone microstructure and geometry in complete-joint-penetration laser-arc hybrid welding of low-alloy steel",
abstract = "The fusion zone geometry and microstructure in complete-joint-penetration hybrid laser gas metal arc welds of a low-alloy steel are examined experimentally and theoretically. Weld geometry and spatially variable cooling rates are investigated using a three-dimensional heat transfer and fluid flow model. Experimentally measured microstructures are compared with those estimated from a microstructure model based on kinetics and thermodynamics of phase transformations, for a range of laser arc separation distances and heat inputs. Considerable variations in both cooling rates and microstructure were observed for the range of process parameters utilized. In fact, the experimental results and calculations show that for the same heat input, a predominantly ferritic and predominantly martensitic microstructure can be obtained, depending on the laser arc separation distance and resulting cooling rate. A process map is constructed showing the effect of welding speed, laser power, and laser arc separation distance on cooling rates and microconstituent volume fractions. The map indicates a martensite-free microstructure can be maintained over a wide range of welding parameters.",
author = "Wei, {H. L.} and Blecher, {J. J.} and Todd Palmer and Tarasankar Debroy",
year = "2015",
month = "4",
day = "1",
language = "English (US)",
volume = "94",
pages = "135s--144s",
journal = "Welding Journal",
issn = "0043-2296",
publisher = "American Welding Society",
number = "4",

}

Fusion zone microstructure and geometry in complete-joint-penetration laser-arc hybrid welding of low-alloy steel. / Wei, H. L.; Blecher, J. J.; Palmer, Todd; Debroy, Tarasankar.

In: Welding Journal, Vol. 94, No. 4, 01.04.2015, p. 135s-144s.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Fusion zone microstructure and geometry in complete-joint-penetration laser-arc hybrid welding of low-alloy steel

AU - Wei, H. L.

AU - Blecher, J. J.

AU - Palmer, Todd

AU - Debroy, Tarasankar

PY - 2015/4/1

Y1 - 2015/4/1

N2 - The fusion zone geometry and microstructure in complete-joint-penetration hybrid laser gas metal arc welds of a low-alloy steel are examined experimentally and theoretically. Weld geometry and spatially variable cooling rates are investigated using a three-dimensional heat transfer and fluid flow model. Experimentally measured microstructures are compared with those estimated from a microstructure model based on kinetics and thermodynamics of phase transformations, for a range of laser arc separation distances and heat inputs. Considerable variations in both cooling rates and microstructure were observed for the range of process parameters utilized. In fact, the experimental results and calculations show that for the same heat input, a predominantly ferritic and predominantly martensitic microstructure can be obtained, depending on the laser arc separation distance and resulting cooling rate. A process map is constructed showing the effect of welding speed, laser power, and laser arc separation distance on cooling rates and microconstituent volume fractions. The map indicates a martensite-free microstructure can be maintained over a wide range of welding parameters.

AB - The fusion zone geometry and microstructure in complete-joint-penetration hybrid laser gas metal arc welds of a low-alloy steel are examined experimentally and theoretically. Weld geometry and spatially variable cooling rates are investigated using a three-dimensional heat transfer and fluid flow model. Experimentally measured microstructures are compared with those estimated from a microstructure model based on kinetics and thermodynamics of phase transformations, for a range of laser arc separation distances and heat inputs. Considerable variations in both cooling rates and microstructure were observed for the range of process parameters utilized. In fact, the experimental results and calculations show that for the same heat input, a predominantly ferritic and predominantly martensitic microstructure can be obtained, depending on the laser arc separation distance and resulting cooling rate. A process map is constructed showing the effect of welding speed, laser power, and laser arc separation distance on cooling rates and microconstituent volume fractions. The map indicates a martensite-free microstructure can be maintained over a wide range of welding parameters.

UR - http://www.scopus.com/inward/record.url?scp=84930144530&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84930144530&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:84930144530

VL - 94

SP - 135s-144s

JO - Welding Journal

JF - Welding Journal

SN - 0043-2296

IS - 4

ER -