Method for measuring nonmetallic inclusion in steel

Abstract

The present invention relates to the technical field of measuring non-metallic inclusions, in particular to a method for measuring non-metallic inclusions in steel, comprising the following steps: (1) sampling; (2) inlaying; (3) grinding; (4) polishing; (5) Cleaning; (6) Corrosion; (7) Microscopic metallographic examination. The method for detecting non-metallic inclusions of the present invention has the advantages of simple operation, mature technology and high measurement accuracy of inclusions, and can meet the use requirements of most domestic manufacturers.

Description

technical field

[0001] The invention relates to the technical field of measuring non-metallic inclusions, in particular to a method for measuring non-metallic inclusions in steel. Background technique

[0002] During the steelmaking process, a small amount of slag, refractory materials and reaction products during smelting may enter molten steel to form non-metallic inclusions. They will reduce the mechanical properties of steel, especially reduce the plasticity, toughness and fatigue limit. In severe cases, they will also cause cracks in the steel during hot working and heat treatment or suddenly brittle fracture during use. Non-metallic inclusions can also promote the formation of hot-processed fibrous and banded structures in steel, making the material anisotropic. In severe cases, the transverse plasticity is only half of the longitudinal plasticity, and the impact toughness of the steel is greatly reduced. Although the content of non-metallic inclusions in steel is sma...

Examples

Embodiment 1

[0059] The method for measuring non-metallic inclusions in steel of the present invention comprises the following steps: (1) Sampling: intercept the sample along the rolling direction or the stretching direction, so that the polished surface area of ​​the sample is 50mm 2 ;(2) Mounting: Put the intercepted sample flat into the mounting machine, put bakelite powder filler, set the temperature at 130±5°C, close the mounting machine, pressurize and keep warm for 5 minutes to form the sample; (3) Grinding: Grind the inlaid sample on the water-grinding sandpaper of the grinder. The water-grinding sandpaper is ground from coarse (80 mesh) to fine (1500 mesh) water-grinding sandpaper to grind off the deformed layer on the surface of the sample until The surface of the sample is smooth; (4) Polishing: the sample is polished on the polishing cloth of the polishing machine, and the polishing liquid is used for polishing. Make the grinding surface a smooth mirror surface without scratche...

Embodiment 2

[0061] The method for measuring non-metallic inclusions in steel of the present invention comprises the following steps: (1) Sampling: intercept the sample along the rolling direction or the stretching direction, so that the polished surface area of ​​the sample is 54mm 2 ;(2) Mounting: Put the intercepted sample flat into the mounting machine, put bakelite powder filler, set the temperature at 130±5°C, close the mounting machine, pressurize and keep warm for 8 minutes to form the sample; (3) Grinding: Grind the inlaid sample on the water-grinding sandpaper of the grinder. The water-grinding sandpaper is ground from coarse (80 mesh) to fine (1500 mesh) water-grinding sandpaper to grind off the deformed layer on the surface of the sample until The surface of the sample is smooth; (4) Polishing: Polish the sample on the polishing cloth of the polishing machine. Polishing liquid is used for polishing. Make the grinding surface a smooth mirror surface without scratches, and the po...

Embodiment 3

[0063] The method for measuring non-metallic inclusions in steel of the present invention comprises the following steps: (1) Sampling: intercept the sample along the rolling direction or the stretching direction, so that the polished surface area of ​​the sample is 54mm 2 ; (2) Mounting: Put the intercepted sample flat into the mounting machine, put in the electric jade powder filler, set the temperature at 120±5°C, close the mounting machine, pressurize and keep warm for 10 minutes to form the sample; (3 ) Grinding: Grind the inlaid sample on the water-grinding sandpaper of the grinder. The water-grinding sandpaper is ground from coarse (80 mesh) to fine (1500 mesh) water-grinding sandpaper to grind off the deformed layer on the surface of the sample. Until the surface of the sample is smooth; (4) Polishing: Polish the sample on the polishing cloth of the polishing machine, and use polishing liquid for polishing during polishing. , so that the grinding surface becomes a smoot...

technical field

[0001] The invention relates to the technical field of measuring non-metallic inclusions, in particular to a method for measuring non-metallic inclusions in steel. Background technique

[0002] During the steelmaking process, a small amount of slag, refractory materials and reaction products during smelting may enter molten steel to form non-metallic inclusions. They will reduce the mechanical properties of steel, especially reduce the plasticity, toughness and fatigue limit. In severe cases, they will also cause cracks in the steel during hot working and heat treatment or suddenly brittle fracture during use. Non-metallic inclusions can also promote the formation of hot-processed fibrous and banded structures in steel, making the material anisotropic. In severe cases, the transverse plasticity is only half of the longitudinal plasticity, and the impact toughness of the steel is greatly reduced. Although the content of non-metallic inclusions in steel is sma...

Examples

Embodiment 1

[0059] The method for measuring non-metallic inclusions in steel of the present invention comprises the following steps: (1) Sampling: intercept the sample along the rolling direction or the stretching direction, so that the polished surface area of ​​the sample is 50mm 2 ;(2) Mounting: Put the intercepted sample flat into the mounting machine, put bakelite powder filler, set the temperature at 130±5°C, close the mounting machine, pressurize and keep warm for 5 minutes to form the sample; (3) Grinding: Grind the inlaid sample on the water-grinding sandpaper of the grinder. The water-grinding sandpaper is ground from coarse (80 mesh) to fine (1500 mesh) water-grinding sandpaper to grind off the deformed layer on the surface of the sample until The surface of the sample is smooth; (4) Polishing: the sample is polished on the polishing cloth of the polishing machine, and the polishing liquid is used for polishing. Make the grinding surface a smooth mirror surface without scratche...

Embodiment 2

[0061] The method for measuring non-metallic inclusions in steel of the present invention comprises the following steps: (1) Sampling: intercept the sample along the rolling direction or the stretching direction, so that the polished surface area of ​​the sample is 54mm 2 ;(2) Mounting: Put the intercepted sample flat into the mounting machine, put bakelite powder filler, set the temperature at 130±5°C, close the mounting machine, pressurize and keep warm for 8 minutes to form the sample; (3) Grinding: Grind the inlaid sample on the water-grinding sandpaper of the grinder. The water-grinding sandpaper is ground from coarse (80 mesh) to fine (1500 mesh) water-grinding sandpaper to grind off the deformed layer on the surface of the sample until The surface of the sample is smooth; (4) Polishing: Polish the sample on the polishing cloth of the polishing machine. Polishing liquid is used for polishing. Make the grinding surface a smooth mirror surface without scratches, and the po...

Embodiment 3

[0063] The method for measuring non-metallic inclusions in steel of the present invention comprises the following steps: (1) Sampling: intercept the sample along the rolling direction or the stretching direction, so that the polished surface area of ​​the sample is 54mm 2 ; (2) Mounting: Put the intercepted sample flat into the mounting machine, put in the electric jade powder filler, set the temperature at 120±5°C, close the mounting machine, pressurize and keep warm for 10 minutes to form the sample; (3 ) Grinding: Grind the inlaid sample on the water-grinding sandpaper of the grinder. The water-grinding sandpaper is ground from coarse (80 mesh) to fine (1500 mesh) water-grinding sandpaper to grind off the deformed layer on the surface of the sample. Until the surface of the sample is smooth; (4) Polishing: Polish the sample on the polishing cloth of the polishing machine, and use polishing liquid for polishing during polishing. , so that the grinding surface becomes a smoot...