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A method for controlling the welding structure of heavy-duty rail

A control method and rail technology, applied in welding equipment, auxiliary welding equipment, welding/cutting auxiliary equipment, etc., can solve the problems that the post-weld cooling rate cannot be realized, and the control effect needs to be investigated, so as to improve the uniformity of the structure and enrich the theory The effect of the system

Active Publication Date: 2021-10-08
NORTHEASTERN UNIV LIAONING
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, the post-weld heat treatment process of this technology is only for natural cooling of the joints in the air, and the control of the post-weld cooling rate cannot be realized. The control effect on the abnormal martensitic structure at the weld remains to be investigated.
[0010] At present, there are many related technologies for controlling the formation of abnormal martensite structure in the rail base metal or welded joints. However, these related technologies have not formulated an accurate heavy-duty rail welding structure for the transformation temperature of the abnormal structure martensite. Control Method

Method used

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  • A method for controlling the welding structure of heavy-duty rail
  • A method for controlling the welding structure of heavy-duty rail
  • A method for controlling the welding structure of heavy-duty rail

Examples

Experimental program
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Effect test

Embodiment 1

[0043] Research on the formation of abnormal martensitic structure at the weld position of bainite rail welded joints:

[0044] Aiming at the problem of abnormal martensitic structure at the welding seam position of the bainite rail after welding, this example focuses on the influence of the cooling rate on the abnormal martensite structure at the welding seam position of the heavy-duty rail after welding The research is the starting point to determine the optimal post-weld cooling system to suppress the formation of abnormal martensitic structure at the weld position at the welded joint.

[0045] Firstly, using the deformation thermal expansion phase transition instrument DIL805, the CTT curves of different phase transitions of the heavy-duty steel rails used at different cooling rates were obtained, so as to obtain the martensite transformation start temperature and martensite transformation end temperature under the corresponding element composition, and then According to t...

Embodiment 2

[0066] Research on the formation of abnormal martensitic structure at the welded joints of hypereutectoid heavy-duty rails:

[0067] Use the formula K1=399.8-11.5×(7.37x) V1 With K2=259.5-14.1×(6.76x) V2 , where, x=C Mn / 12+Cr / 35+Ni / 21+Mo / 20+Si / 40-V / 3-Al / 21, V1 is the cooling of the martensitic transformation start temperature K1 after welding Rate (K / s), V1 is 3-5K / s, in calculation, V1=4K / s, V2 is the cooling rate (K / s) that martensite transformation start temperature K1 cools to martensite transformation end temperature K2 ), V2=0.3K / s; calculated, the martensite transformation start temperature K1 is 611.54K, and the martensite transformation end temperature K2 is 520.86K.

[0068] After welding the eutectoid heavy-duty rail joint, during the cooling process of the welded joint, control the cooling process of the weld position at the welded joint; specifically, the following steps are included:

[0069] Step 1: According to the calculated martensite transformation start ...

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Abstract

The invention discloses a method for controlling the welding structure of heavy-duty rails, which belongs to the field of railway rail welding. The control method is to first determine the corresponding martensite transformation start temperature K1 and martensite transformation end temperature K2 according to the mass percentage of each element in the heavy-duty steel rail used and the cooling rate to be adopted; Control the cooling rate of the welding seam position at the welding joint to 3-10K / s. When the temperature cools to K1+(30-60)K, control the temperature of the welding seam position at the welding joint to reduce the cooling of the welding seam position at the welding joint Rate <1.0K / s; when the temperature continues to cool down to K2, let it cool down to ambient temperature naturally. This method is based on heavy-duty rails with different compositions. By controlling the cooling rate and K1 and K2 of the welded joints at the welded joints of the rails, the abnormal martensitic structure at the welded joints at the welded joints of the rails is effectively suppressed, which can significantly improve the quality of the welded joints of the rails. tissue uniformity.

Description

technical field [0001] The invention belongs to the technical field of railway rail welding, and in particular relates to a method for controlling the welding structure of heavy-duty rails. Background technique [0002] At present, heavy-duty lines such as the Daqin Railway, the Waji Railway, and the Menghua Railway constitute a new national strategic transportation network, which has become the main artery of my country's economic and social development. At the same time, the improvement of heavy-haul railway transportation capacity also puts forward higher requirements for the smoothness, weldability and wear resistance of steel rails, that is, seamless railways with long service life should be built. At this time, new heavy-duty rails such as bainite rails and hypereutectoid rails with excellent comprehensive mechanical properties such as high strength, high toughness, and high wear resistance have gradually become the first choice for heavy-haul railway project construct...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B23K37/00B23K37/02
CPCB23K37/003B23K37/02
Inventor 祭程关锐朱苗勇陈天赐
Owner NORTHEASTERN UNIV LIAONING
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