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ML00067 - May.2017donated by: David Hadjadj

Cold Cracks in C-Mn SAW Weld Metal

Micrography of the fractured region in the center of the fillet weld metal, that is hard due to the increase in the Mn and Si contents.

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of the fractured region in the center of the metal, that is hard due to the increase in the and contents.
M

Material

CMn Steel
  • UNS G10080
  • UNS G15240
Ds

Description

During fabrication of an component using overlap between a (superior) and a C- plate (inferior) a occurred in the after , due to the adoption of an in a condition where a cleaning effect was not required, increasing the Mn and contents in the weld metal and forming a hard martensitic .

C

Chemistry (% in weight)

8 mm plate

0.06C; 0.02Si; 0.26Mn; 0.008P; 0.013S; 0.005Nb; 0.003Ti; 0.002V; 0.04Cr; 0.02Cu; 0.050Al.

12 mm plate

0.18C; 0.17Si; 1.42Mn; 0.023P; 0.004S; 0.043Nb; 0.003Ti; 0.02Cr; 0.02Cu.

Weld Metal - Non Cracked

0.10C; 0.50Si; 1.29Mn; 0.026P; 0.017S; 0.020Nb; 0.03Cr; 0.04Ni; 0.01Mo; 0.06Cu.

Cracked Weld Metal

0.13C; 0.75Si; 1.83Mn; 0.026P; 0.019S; 0.025Nb; 0.04Cr; 0.04Ni; 0.02Mo; 0.07Cu.

Associated Images
Micrography of the weld metal presenting a martensitic island with microcracks, due to a localized increase in the manganese and silicon content, probably because an active flux was adopted in a condition where a high cleanning action was not required. A high flux-to-wire ratio (>1) could also be an issue.
795
VIEW
ML00067 / May.2017
Cold Cracks in C-Mn SAW Weld Metal
M - CMn SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Microcracks
Aspect of the fillet weld between the superior plate (Low carbon 8 mm thick) and the inferior plate (C-Mn 12 mm thick), in an overlap geometry. In this region the welded joint was sound.
90
VIEW
ML00067 / May.2017
Cold Cracks in C-Mn SAW Weld Metal
M - CMn SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - Aspect Before AnalysisDf - Welded Joint
Aspect of the fracture in the middle of the fillet weld between the superior plate (Low carbon 8 mm thick no longer there) and the inferior plate (C-Mn 12 mm thick), in an overlap geometry.
77
VIEW
ML00067 / May.2017
Cold Cracks in C-Mn SAW Weld Metal
M - CMn SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - Aspect Before AnalysisDf - Fracture
Macrography of the joint welded by SAW process in overlap geometry, between the 8 mm low carbon steel plate (superior) and the 12 mm C-Mn steel plate (inferior).
70
VIEW
ML00067 / May.2017
Cold Cracks in C-Mn SAW Weld Metal
M - CMn SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - NItal Etched MacroDf - Welded Joint
Micrography of the 12 mm plate base metal, carbon-manganese steel. Ferritic-perlitic structure, refined.
58
VIEW
ML00067 / May.2017
Cold Cracks in C-Mn SAW Weld Metal
M - CMn SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Base Metal
Micrography of the 8 mm plate base metal, low carbon steel. Predominantly ferritic structure.
57
VIEW
ML00067 / May.2017
Cold Cracks in C-Mn SAW Weld Metal
M - CMn SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Base Metal
Macrography of the welded joint in a non cracked region.
57
VIEW
ML00067 / May.2017
Cold Cracks in C-Mn SAW Weld Metal
M - CMn SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - NItal Etched MacroDf - Welded Joint
Micrography of the weld metal in the center of the fillet. Typical ferritic structure and typical low carbon chemistry.
51
VIEW
ML00067 / May.2017
Cold Cracks in C-Mn SAW Weld Metal
M - CMn SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Weld Metal
Micrography of the weld metal in a non cracked region. Ferritic weld metal presenting hardness level about 220 HV1.
45
VIEW
ML00067 / May.2017
Cold Cracks in C-Mn SAW Weld Metal
M - CMn SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Weld Metal
Micrographic detail of the weld metal in a non cracked region. Ferritic weld metal presenting hardness level about 220 HV1.
46
VIEW
ML00067 / May.2017
Cold Cracks in C-Mn SAW Weld Metal
M - CMn SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Weld Metal
Macrography of the welded joint in a cracked region.
49
VIEW
ML00067 / May.2017
Cold Cracks in C-Mn SAW Weld Metal
M - CMn SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - NItal Etched MacroDf - Welded Joint
Micrography of the fractured region in the center of the fillet weld metal, that is hard due to the increase in the Mn and Si contents.
43
VIEW
ML00067 / May.2017
Cold Cracks in C-Mn SAW Weld Metal
M - CMn SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Fracture
Micrography of the weld metal in a hardened region. Martensitic weld metal presenting macro hardness level about 370 HV1.
41
VIEW
ML00067 / May.2017
Cold Cracks in C-Mn SAW Weld Metal
M - CMn SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Weld Metal
Micrographic detail of the weld metal in a hardened region. Martensitic weld metal presenting hardness level about 370 HV1.
39
VIEW
ML00067 / May.2017
Cold Cracks in C-Mn SAW Weld Metal
M - CMn SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Weld Metal
Micrography of the weld metal in a cracked region.
41
VIEW
ML00067 / May.2017
Cold Cracks in C-Mn SAW Weld Metal
M - CMn SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Cracks
Micrographic detail of the weld metal in a cracked region.
77
VIEW
ML00067 / May.2017
Cold Cracks in C-Mn SAW Weld Metal
M - CMn SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Cracks
Micrography of the weld metal in a cracked region. Non tempered martensitic regions. This part is not typically stress relieved after welding.
51
VIEW
ML00067 / May.2017
Cold Cracks in C-Mn SAW Weld Metal
M - CMn SteelP - Fabrication WeldAp - AutomotiveCd - Welding Defect
Cm - Nital Etched Micrography by OMDf - Martensite