Comprehensive evaluation method for welding hot crack sensitivity

A comprehensive evaluation, hot cracking technology, applied in welding equipment, auxiliary welding equipment, welding/cutting auxiliary equipment, etc., can solve the problem that the welding hot crack sensitivity evaluation method cannot be better at the same time evaluate solidification cracks, liquefaction cracks and stalling Cracks and other problems, to achieve the effect of true and reliable test results, easy identification, and simple methods

Active Publication Date: 2021-03-02
SHANGHAI JIAO TONG UNIV +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0005] The purpose of the present invention is to solve the problem that the current evaluation method of welding hot crack sensitivity cannot evaluate solidification cracks, liquefaction cracks and loss cracks at the same time, and provide a comprehensive evaluation method for welding hot crack sensitivity, which can simultaneously evaluate Susceptibility to solidification cracks, liquefaction cracks and high temperature loss cracks

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  • Comprehensive evaluation method for welding hot crack sensitivity

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Effect test

Embodiment 1

[0031] In this embodiment, nickel-based alloy material is taken as an example to evaluate its sensitivity to welding hot cracks. The specific method includes the following steps:

[0032] (1) Taking nickel-based alloys as an example, wire-cutting samples with a size of 120×40×6mm, the number is 8 to 10 pieces, figure 1 A schematic diagram of the sample.

[0033] (2) The surface of the sample is ground step by step with 80-2000 mesh sandpaper, and then the central area with a length and width of 15 mm is polished, and the microstructure is slightly etched with corrosive liquid. Cracks and no obvious scratches.

[0034] (3) Place the sample on a variable restraint testing machine, which is equipped with an argon arc welding power source, and adjust the sample so that the tungsten electrode is facing the center of the sample.

[0035] (4) Use an argon arc welding machine to remelt the center of the sample by arc fixed-point welding. The spot welding current is 80A, the spot wel...

Embodiment 2

[0043] This embodiment takes austenitic stainless steel as an example to evaluate its sensitivity to welding hot cracks. The specific method includes the following steps:

[0044] (1) Wire-cut processing of samples with a size of 150×50×8 mm, the number of which is 8 to 10 pieces.

[0045] (2) The surface of the sample is ground step by step with 80-2000 mesh sandpaper, and then the central area with a length and width of 25 mm is polished, and the microstructure is slightly etched with corrosive liquid. Observe the area under a 500-fold microscope. Cracks and no obvious scratches.

[0046] (3) Place the sample on a variable restraint testing machine, which is equipped with an argon arc welding power source, and adjust the sample so that the tungsten electrode is facing the center of the sample.

[0047](4) Use an argon arc welding machine to remelt the center of the sample by arc fixed-point welding. The spot welding current is 100A, the spot welding voltage is 15V, the spot...

Embodiment 3

[0055] This embodiment takes austenitic stainless steel as an example to evaluate its sensitivity to welding hot cracks. The specific method includes the following steps:

[0056] (1) Wire-cut processing samples with a size of 100×30×4mm, and the number is 8 to 10 pieces.

[0057] (2) The surface of the sample is ground step by step with 80-2000 mesh sandpaper, and then the central area with a length and width of 10 mm is polished, and the microstructure is slightly etched with corrosive liquid, and the area is observed under a 500 times microscope. Cracks and no obvious scratches.

[0058] (3) Place the sample on a variable restraint testing machine, which is equipped with an argon arc welding power source, and adjust the sample so that the tungsten electrode is facing the center of the sample.

[0059] (4) Use an argon arc welding machine to remelt the center of the sample by arc fixed-point welding. The spot welding current is 60A, the spot welding voltage is 8V, the spot ...

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Abstract

The invention discloses a comprehensive evaluation method for welding hot crack sensitivity. The method can be used for simultaneously evaluating hot cracks such as solidification cracks, liquefactioncracks, high-temperature delayed cracks and the like in the welding process, and is suitable for austenitic stainless steel and nickel-based materials. Fixed-point welding and arc extinguishing are carried out at the center of a sample, then bending is carried out, an optical microscope is adopted to observe areas near a weld joint and a fusion line, hot crack types are distinguished, the numberof cracks of different types, the total length of the cracks, the maximum length of the cracks, the crack distribution range and the like are counted, and a corresponding relation with strain is established, so the sensitivity of different types of hot cracks is evaluated. The method is simple, the hot crack type is easy to distinguish, the cost is low, the test result is real and reliable, and the method has important significance for evaluating the welding hot crack sensitivity.

Description

technical field [0001] The invention relates to the field of testing metal material welding hot crack sensitivity, in particular to a comprehensive evaluation method for welding hot crack sensitivity. Background technique [0002] Welding thermal cracks, such as solidification cracks, liquefaction cracks and high temperature loss cracks, mostly occur at high temperatures close to the solidus. Among them, the solidification crack occurs during the solidification process of the weld pool. Due to rapid cooling, the segregated liquid phase layer remains between the dendrites. At the same time, when the place is subjected to deformation, there is no sufficient liquid phase to supplement the thermal cracks, which are located at the solidification grain boundary. Above; liquefaction cracks occur near the fusion line. Due to the welding heat cycle, the low melting point material at the grain boundary melts, and cracks are formed under the action of external force; loss of extension ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N3/20G01N3/02G01N1/32B23K37/00
CPCB23K37/00G01N1/32G01N3/02G01N3/20G01N2203/0003G01N2203/0023G01N2203/0062G01N2203/0216G01N2203/0226G01N2203/024G01N2203/0258G01N2203/0282G01N2203/0298G01N2203/0641G01N2203/0676G01N2203/0682
Inventor 余春陆皓王军寒余志远徐济进陈俊梅谷雨张俊宝黄逸峰
Owner SHANGHAI JIAO TONG UNIV
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