Effect of shielding gas on the properties and microstructure of melted steel surface using a TIG torch

Patricia Munoz De Escalona, Shahjahan Mridha, neville Baker

Research output: Contribution to conferencePaper

Abstract

A surface engineering technique based on a Tungsten Inert Gas (TIG) torch was used to melt single tracks on the surface of a micro-alloyed steel with a hardness of 150 HV. The influenceof three shielding gases, argon, helium and
nitrogen, on the microstructure and hardness of the re-solidified surfaces was analyzed. In all melting techniques, the heat generated by the source is normally conducted to the substrate ahead of the torch, and has been described as ‘preheat’. This leads to a gradually higher substrate temperature, from the start to the finish of a melted surface track. The aim of this research was to analyze any inhomogeneities in the microstructure, due to ‘preheat’, which is rarely considered in the published literature. Three thermocouples were located along the melted track in order to record the temperature at three different points. An energy input of ~ 840J/mm was used in each experiment and the results show that the maximum temperature recorded by the last thermocouple, No three (subjected to the preheat), for argon, helium and nitrogen gas was 590 ºC, 1120º C and 740ºC respectively, where a difference of 150ºC and 200 ºC was registered between the first and thirdthermocouples when using helium and nitrogen respectively. The corresponding hardness values were 170 HV, 162 HV and 225HV, and the corresponding surface roughness values were 6 μm, 12μm and 25μm. A decrease of almost 60% in the roughness value was observed between the initial and last stage of the melted track, when using argon as shielding gas.

Conference

ConferenceInternational Conference on Advances in Materials and Processing Technologies, AMPT 2014
CountryUnited Arab Emirates
CityDubai
Period16/11/1420/11/14

Fingerprint

Noble Gases
Tungsten
Steel
Inert gases
Shielding
Helium
Argon
Gases
Microstructure
Hardness
Thermocouples
Nitrogen
Surface roughness
Substrates
Temperature
Melting
Experiments

Keywords

  • surface engineering
  • shielding gas
  • TIG torch
  • surface roughness

Cite this

Munoz De Escalona, P., Mridha, S., & Baker, N. (2014). Effect of shielding gas on the properties and microstructure of melted steel surface using a TIG torch. Paper presented at International Conference on Advances in Materials and Processing Technologies, AMPT 2014, Dubai, United Arab Emirates.
Munoz De Escalona, Patricia ; Mridha, Shahjahan ; Baker, neville. / Effect of shielding gas on the properties and microstructure of melted steel surface using a TIG torch. Paper presented at International Conference on Advances in Materials and Processing Technologies, AMPT 2014, Dubai, United Arab Emirates.10 p.
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abstract = "A surface engineering technique based on a Tungsten Inert Gas (TIG) torch was used to melt single tracks on the surface of a micro-alloyed steel with a hardness of 150 HV. The influenceof three shielding gases, argon, helium andnitrogen, on the microstructure and hardness of the re-solidified surfaces was analyzed. In all melting techniques, the heat generated by the source is normally conducted to the substrate ahead of the torch, and has been described as ‘preheat’. This leads to a gradually higher substrate temperature, from the start to the finish of a melted surface track. The aim of this research was to analyze any inhomogeneities in the microstructure, due to ‘preheat’, which is rarely considered in the published literature. Three thermocouples were located along the melted track in order to record the temperature at three different points. An energy input of ~ 840J/mm was used in each experiment and the results show that the maximum temperature recorded by the last thermocouple, No three (subjected to the preheat), for argon, helium and nitrogen gas was 590 ºC, 1120º C and 740ºC respectively, where a difference of 150ºC and 200 ºC was registered between the first and thirdthermocouples when using helium and nitrogen respectively. The corresponding hardness values were 170 HV, 162 HV and 225HV, and the corresponding surface roughness values were 6 μm, 12μm and 25μm. A decrease of almost 60{\%} in the roughness value was observed between the initial and last stage of the melted track, when using argon as shielding gas.",
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Munoz De Escalona, P, Mridha, S & Baker, N 2014, 'Effect of shielding gas on the properties and microstructure of melted steel surface using a TIG torch' Paper presented at International Conference on Advances in Materials and Processing Technologies, AMPT 2014, Dubai, United Arab Emirates, 16/11/14 - 20/11/14, .

Effect of shielding gas on the properties and microstructure of melted steel surface using a TIG torch. / Munoz De Escalona, Patricia; Mridha, Shahjahan; Baker, neville.

2014. Paper presented at International Conference on Advances in Materials and Processing Technologies, AMPT 2014, Dubai, United Arab Emirates.

Research output: Contribution to conferencePaper

TY - CONF

T1 - Effect of shielding gas on the properties and microstructure of melted steel surface using a TIG torch

AU - Munoz De Escalona, Patricia

AU - Mridha, Shahjahan

AU - Baker, neville

PY - 2014/11/16

Y1 - 2014/11/16

N2 - A surface engineering technique based on a Tungsten Inert Gas (TIG) torch was used to melt single tracks on the surface of a micro-alloyed steel with a hardness of 150 HV. The influenceof three shielding gases, argon, helium andnitrogen, on the microstructure and hardness of the re-solidified surfaces was analyzed. In all melting techniques, the heat generated by the source is normally conducted to the substrate ahead of the torch, and has been described as ‘preheat’. This leads to a gradually higher substrate temperature, from the start to the finish of a melted surface track. The aim of this research was to analyze any inhomogeneities in the microstructure, due to ‘preheat’, which is rarely considered in the published literature. Three thermocouples were located along the melted track in order to record the temperature at three different points. An energy input of ~ 840J/mm was used in each experiment and the results show that the maximum temperature recorded by the last thermocouple, No three (subjected to the preheat), for argon, helium and nitrogen gas was 590 ºC, 1120º C and 740ºC respectively, where a difference of 150ºC and 200 ºC was registered between the first and thirdthermocouples when using helium and nitrogen respectively. The corresponding hardness values were 170 HV, 162 HV and 225HV, and the corresponding surface roughness values were 6 μm, 12μm and 25μm. A decrease of almost 60% in the roughness value was observed between the initial and last stage of the melted track, when using argon as shielding gas.

AB - A surface engineering technique based on a Tungsten Inert Gas (TIG) torch was used to melt single tracks on the surface of a micro-alloyed steel with a hardness of 150 HV. The influenceof three shielding gases, argon, helium andnitrogen, on the microstructure and hardness of the re-solidified surfaces was analyzed. In all melting techniques, the heat generated by the source is normally conducted to the substrate ahead of the torch, and has been described as ‘preheat’. This leads to a gradually higher substrate temperature, from the start to the finish of a melted surface track. The aim of this research was to analyze any inhomogeneities in the microstructure, due to ‘preheat’, which is rarely considered in the published literature. Three thermocouples were located along the melted track in order to record the temperature at three different points. An energy input of ~ 840J/mm was used in each experiment and the results show that the maximum temperature recorded by the last thermocouple, No three (subjected to the preheat), for argon, helium and nitrogen gas was 590 ºC, 1120º C and 740ºC respectively, where a difference of 150ºC and 200 ºC was registered between the first and thirdthermocouples when using helium and nitrogen respectively. The corresponding hardness values were 170 HV, 162 HV and 225HV, and the corresponding surface roughness values were 6 μm, 12μm and 25μm. A decrease of almost 60% in the roughness value was observed between the initial and last stage of the melted track, when using argon as shielding gas.

KW - surface engineering

KW - shielding gas

KW - TIG torch

KW - surface roughness

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M3 - Paper

ER -

Munoz De Escalona P, Mridha S, Baker N. Effect of shielding gas on the properties and microstructure of melted steel surface using a TIG torch. 2014. Paper presented at International Conference on Advances in Materials and Processing Technologies, AMPT 2014, Dubai, United Arab Emirates.