Monitoring device and monitoring method for simulating welding joint corrosion in stress state

Abstract

The invention relates to a monitoring device and a monitoring method for simulating welding joint corrosion in a stress state. The device comprises a four-point bending augmentor, a zero resistance galvanometer, an electrochemical workstation, a welding resistance-multi-electrode corrosion sensor, a reference electrode, an auxiliary electrode, a microhmmeter and a signal acquisition control system, wherein the welding resistance-multi-electrode corrosion sensor comprises a corrosion element and a reference element; the corrosion element is adapted with a relay switch, and is coupled by the zero resistance galvanometer; the electrode element is connected to the microhmmeter; the stress level of the four-point bending augmentor is changed by adjusting the deflection of a long-strip electrode specimen; the signal acquisition control system is used for acquiring and storing data measured by the zero resistance galvanometer and the microhmmeter, and controlling the action of the relay switch. The monitoring device and the monitoring method disclosed by the invention have the advantages that the corrosion condition of a welding joint area of a pipeline can be comprehensively and accurately monitored, and the total corrosion depth and the corrosion rate of the welding joint area and the electrochemical corrosion rate are measured; in addition, the cathode and anode current in different regions of the welding joint is monitored, and the stress condition of a welding joint node is simulated.

Description

technical field [0001] The invention relates to a device that can be used for monitoring local corrosion of welds, in particular, a device and method for monitoring corrosion of welds that can simulate a stressed state. Background technique [0002] Weld corrosion problems commonly exist in ships, offshore engineering platforms, oil and gas pipelines, and seawater desalination systems. The welded structure is mainly divided into base metal area, weld area and heat-affected zone. The welding structure is complex, and the chemical composition and organizational structure are different in different regions. Residual stress is easily generated inside the structure, and the welding structure is often an area of ​​stress concentration. These reasons are likely to lead to increased corrosion of welded structures. [0003] Chinese patent document CN106066353A discloses a flexible array reference electrode and its application in situ to study the corrosion method of metal weld seam...

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Problems solved by technology

[0005] However, the weld structure is usually a stress concentration area in the entire structure, so it will inevitably bear external loads. At present, there are few devices and methods for studying corrosion problems in different regions of welds under stress.

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