Residual stresses in thermite welded rails: significance of additional forging
Artikel i vetenskaplig tidskrift, 2020

The aluminothermic welding (ATW) process is the most commonly used welding process for welding rails (track) in the field. The large amount of weld metal added in the ATW process may result in a wide uneven surface zone on the rail head, which may, in rare cases, lead to irregularities in wear and plastic deformation due to high dynamic wheel-rail forces as wheels pass. The present paper studies the introduction of additional forging to the ATW process, intended to reduce the width of the zone affected by the heat input, while not creating a more detrimental residual stress field. Simulations using a novel thermo-mechanical FE model of the ATW process show that addition of a forging pressure leads to a somewhat smaller width of the zone affected by heat. This is also found in a metallurgical examination, showing that this zone (weld metal and heat-affected zone) is fully pearlitic. Only marginal differences are found in the residual stress field when additional forging is applied. In both cases, large tensile residual stresses are found in the rail web at the weld. Additional forging may increase the risk of hot cracking due to an increase in plastic strains within the welded area.

Hardness

FEM

Residual stress

Pearlite

Aluminothermic welding

Författare

Lennart Josefson

Chalmers, Industri- och materialvetenskap, Material- och beräkningsmekanik

Roeland Bisschop

Chalmers, Industri- och materialvetenskap, Material- och beräkningsmekanik

M. Messaadi

TU Delft

J. Hantusch

Goldschmidt Thermit Group

Welding in the World, Le Soudage Dans Le Monde

0043-2288 (ISSN)

Vol. 64 7 1195-1212

WRIST

Europeiska kommissionen (Horisont 2020), 2015-10-01 -- 2018-09-30.

Ämneskategorier

Bearbetnings-, yt- och fogningsteknik

Annan materialteknik

Metallurgi och metalliska material

DOI

10.1007/s40194-020-00912-4

Mer information

Senast uppdaterat

2020-07-03