Method for testing seawater corrosion of low-alloy steel under stress state

A low-alloy steel, stress state technology, applied in the direction of weather resistance/light resistance/corrosion resistance, using stable tension/pressure test material strength, measuring devices, etc., can solve the problem that there are no identical or similar technical records or literature reports, Can not use seawater natural environment test and other problems to achieve the effect of favorable corrosion research means

Inactive Publication Date: 2014-08-06
中国船舶重工集团公司第七二五研究所青岛分部
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, the stress corrosion test devices described in the above-mentioned patented technologies cannot be used for seawater natural environment tests.
So far, in the field of metal material corrosion te

Method used

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  • Method for testing seawater corrosion of low-alloy steel under stress state
  • Method for testing seawater corrosion of low-alloy steel under stress state
  • Method for testing seawater corrosion of low-alloy steel under stress state

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0025] Choose 316L stainless steel to process the outer support 7 and the inner support 5, and the inner fulcrum 3 and the outer fulcrum 2 adopt Bakelite with a diameter of 5 mm. The test material is TC4, and the size of sample 4 is 2×15×110mm. Clamp the sample 4 between the inner fulcrum 3 and the outer fulcrum 2, insert the tightening rod 8 into the end of the screw micrometer positioning bolt 6, rotate the tightening rod 8 around, so that the spiral micrometer positioning bolt 6 is lifted by 4mm, calculate according to the formula It is obtained that the stress on the sample is 675Mpa. Connect the wires at both ends of the sample 4 to the potential measuring device 9, soak the constant strain loading test device in natural seawater, and start the potential measurement. image 3 It is a comparison chart of stress-strain curves tested in this embodiment.

Embodiment 2

[0027] Choose 316L stainless steel to process the outer support 7 and the inner support 5, and the inner fulcrum 3 and the outer fulcrum 2 adopt Bakelite with a diameter of 5 mm. The test material is TC4, and the size of sample 4 is 2×20×110mm. Clamp the sample 4 between the inner fulcrum 3 and the outer fulcrum 2, insert the tightening rod 8 into the end of the screw micrometer positioning bolt 6, and rotate the tightening rod 8 around to lift the screw micrometer positioning bolt 6 by 6.2mm, according to the formula The calculated stress on the sample is 855Mpa. Install 6 sets of samples 4 under stress state according to the above steps, install 6 sets of constant strain loading devices on the sample holder 10, fix the position with the fixing buckle 12, connect the wires at both ends of the sample 4 to the multi-channel potential detection instrument , place the sample rack 10 in the full immersion area of ​​Qingdao Maidao Seawater Test Station, and start the potential in-...

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Abstract

The invention relates to a method for testing seawater corrosion of low-alloy steel under a stress state. The method comprises two steps: 1, loading a constant strain by adopting four-point bending, bending a sample by a spiral micrometer setting bolt, and measuring a flexibility; and 2, installing a plurality of constant-strain loading devices on a real sea sample charging frame with a slot, and installing a multichannel potential acquiring device, and performing potential monitoring in a natural seawater or deep sea environment. The method for testing the seawater corrosion of the low-alloy steel under the stress state, provided by the invention, is capable of realizing evaluation of stress corrosion performance of a stress member under a natural environment, and can be applied to research of a material stress corrosion mechanism in a laboratory. The invention provides a novel testing method for the research of the stress corrosion performance of a stress structure in a service working condition; by adopting test data obtained by the method, the corrosion rule of the material and the member under the working condition can be actually reflected, and a favorable corrosion research means is provided for the research of a use material in the working condition.

Description

technical field [0001] The invention relates to a seawater corrosion test method for low-alloy steel under a stress state, belonging to the field of metal material corrosion test methods. Background technique [0002] Low-alloy steel has high strength, good toughness and excellent welding performance, and is widely used in ships and ship-borne equipment, coastal buildings, docks and offshore platforms and other structures. High salinity, high humidity, and heavily polluted marine environment make corrosion an important factor affecting and restricting the safe use of ships and marine engineering equipment. A common form of corrosion in low alloy steel is generalized corrosion, but ships and marine engineering structures are generally not subject to failure due to generalized corrosion. Due to the complexity of service conditions, local corrosion such as ulcers and pitting corrosion often occurs in low-alloy steel structures. The most dangerous form of damage is stress corro...

Claims

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Application Information

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IPC IPC(8): G01N17/00G01N3/08
Inventor 张慧霞郭为民侯健
Owner 中国船舶重工集团公司第七二五研究所青岛分部
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