Corrosive for original austenite grain boundary of superhigh strength alloy structure steel and display method of original austenite grain boundary

Abstract

The invention belongs to the technical field of metallographic structure observation, and particularly relates to a display method for an original austenite grain boundary of superhigh strength alloy structure D6AE steel. A corrosive for the austenite grain boundary of the superhigh strength alloy structure steel comprises the following components in parts by weight: 4.5 to 5.5 parts of picric acid, 7.5 to 8.5 parts of fatty alcohol-polyoxyethylene ether, 1.8 to 2.8 parts of ammonium cupric chloride, 100 parts of water and 6.6 to 8.1 parts of hydrogen peroxide. By the adoption of the corrosive disclosed by the invention, crystalline grains of original austenite of the superhigh strength alloy structure D6AE steel can be displayed clearly, and thus the problem that the original austenite grain boundary of the D6AE steel is difficult to display is solved.

Description

technical field

[0001] The invention belongs to the technical field of metallographic structure observation, and in particular relates to a method for displaying the original austenite grain boundary of ultra-high-strength alloy structural steel D6AE steel. Background technique

[0002] Ultra-high-strength alloy structural steel D6AE is a low-alloy ultra-high-strength steel for aerospace. It is widely used in the manufacture of missile engine shells and aircraft structural parts. It belongs to medium-carbon chromium-nickel-manganese steel. Due to its extremely high requirements on strength, impact toughness, fracture toughness and stress corrosion resistance, it is generally smelted by double vacuum method of vacuum induction + vacuum arc remelting or electroslag remelting method. Sulfur, phosphorus, The content of impurity elements such as arsenic, selenium, and lead is very low, and the impurity elements that diffuse and segregate from the inside of the grain to the edge o...

Examples

Embodiment 1

[0033] Example 1: Determination of the prior austenite grain size of a certain D6AE forging

[0034] The technological process and steps of the present embodiment are as follows:

[0035] 1. Heat treatment: Process the D6AE forging into a test sample of 10mm×15mm×20mm, place it in a box-type resistance furnace heated to 575°C, keep it warm for 120 minutes, and then cool it to 450°C before taking it out of the furnace and air cooling to room temperature;

[0036] 2. Grinding and polishing: Take the tempered test sample to the grinder for preliminary grinding. After the rough ground test sample is rinsed with clean water, put the grinding surface in turn on each gold plate from coarse to fine. Finely polish on the same sandpaper; each time the next finer sandpaper is changed, the test sample should be rotated 90° for grinding; finally, the ground test sample should be washed and polished on a polishing machine to make the test sample The observation surface achieves a mirror ef...

Embodiment 2

[0044] Example 2: Determination of the grain size of prior austenite in a certain D6AE steel pipe

[0045] The technological process and steps of the present embodiment are as follows:

[0046] 1. Heat treatment: Process the D6AE steel pipe into a test sample of 10mm×10mm×20mm, place it in a box-type resistance furnace heated to 585°C, keep it warm for 600 minutes, and then cool it to 200°C before taking it out of the furnace and air cooling to room temperature;

[0047] 2. Grinding and polishing: Take the tempered test sample to the grinder for preliminary grinding. After the rough ground test sample is rinsed with clean water, put the grinding surface on the metallographic scale from coarse to fine. Carry out fine grinding on the sandpaper; each time the next finer sandpaper is changed, the test sample should be rotated 90° for grinding; finally, the ground test sample should be washed and polished on a polishing machine, so that the test sample can be observed The surface ...

technical field

[0001] The invention belongs to the technical field of metallographic structure observation, and in particular relates to a method for displaying the original austenite grain boundary of ultra-high-strength alloy structural steel D6AE steel. Background technique

[0002] Ultra-high-strength alloy structural steel D6AE is a low-alloy ultra-high-strength steel for aerospace. It is widely used in the manufacture of missile engine shells and aircraft structural parts. It belongs to medium-carbon chromium-nickel-manganese steel. Due to its extremely high requirements on strength, impact toughness, fracture toughness and stress corrosion resistance, it is generally smelted by double vacuum method of vacuum induction + vacuum arc remelting or electroslag remelting method. Sulfur, phosphorus, The content of impurity elements such as arsenic, selenium, and lead is very low, and the impurity elements that diffuse and segregate from the inside of the grain to the edge o...

Examples

Embodiment 1

[0033] Example 1: Determination of the prior austenite grain size of a certain D6AE forging

[0034] The technological process and steps of the present embodiment are as follows:

[0035] 1. Heat treatment: Process the D6AE forging into a test sample of 10mm×15mm×20mm, place it in a box-type resistance furnace heated to 575°C, keep it warm for 120 minutes, and then cool it to 450°C before taking it out of the furnace and air cooling to room temperature;

[0036] 2. Grinding and polishing: Take the tempered test sample to the grinder for preliminary grinding. After the rough ground test sample is rinsed with clean water, put the grinding surface in turn on each gold plate from coarse to fine. Finely polish on the same sandpaper; each time the next finer sandpaper is changed, the test sample should be rotated 90° for grinding; finally, the ground test sample should be washed and polished on a polishing machine to make the test sample The observation surface achieves a mirror ef...

Embodiment 2

[0044] Example 2: Determination of the grain size of prior austenite in a certain D6AE steel pipe

[0045] The technological process and steps of the present embodiment are as follows:

[0046] 1. Heat treatment: Process the D6AE steel pipe into a test sample of 10mm×10mm×20mm, place it in a box-type resistance furnace heated to 585°C, keep it warm for 600 minutes, and then cool it to 200°C before taking it out of the furnace and air cooling to room temperature;

[0047] 2. Grinding and polishing: Take the tempered test sample to the grinder for preliminary grinding. After the rough ground test sample is rinsed with clean water, put the grinding surface on the metallographic scale from coarse to fine. Carry out fine grinding on the sandpaper; each time the next finer sandpaper is changed, the test sample should be rotated 90° for grinding; finally, the ground test sample should be washed and polished on a polishing machine, so that the test sample can be observed The surface ...

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