CN103471900A - Corrosive for displaying billet rimholes and preparation method thereof - Google Patents

Abstract

The invention provides a corrosive for displaying billet rimholes and a preparation method thereof. The corrosive is composed of the following components: 10-25 g of ferric chloride, 50-100 ml of absolute ethyl alcohol, 4-6 ml of nitric acid, 15-30 ml of hydrochloric acid and 0.8-1.0 g of copper chloride. The reparation method comprises the following steps: placing a ferric chloride solid in a glass container, and adding 2000 ml of distilled water to dissolve the ferric chloride solid; adding absolute ethyl alcohol into the ferric chloride aqueous solution, uniformly stirring and sequentially adding nitric acid and hydrochloric acid; finally, adding a specified amount of copper chloride, and fully stirring to prepare a finished product corrosive. The corrosive provided by the invention is high in inspection speed, small in pollution, energy-saving, simple and convenient to operate, weak in selective corrosion on a steel matrix and capable of clearly displaying the distribution, sizes and forms of the rimholes in a macrostructure of the billet in original appearance, thereby improving the inspection rate of the rimhole defect, avoiding the inspection omission phenomenon and reducing the quality loss in subsequent procedures.

Description

A kind of mordant and compound method thereof that shows the steel billet rimhole

Technical field

The invention belongs to inspection laboratory reagent field, be specifically related to a kind of for showing mordant and the compound method thereof of casting steel billet macrostructure rimhole defect form.

Background technology

The rimhole of steel billet is more common defect, when the size of rimhole defect greatly to a certain extent the time, can not seam in the follow-up operation of rolling, usually on the finished product material surface after rolling with pipe, stick up skin or be mingled with a bunch form and display, have a strong impact on product quality and usability.For hot-rolled sheet coil, in heating and the operation of rolling, if bubble exposes and oxidation, may form crimping, fly the line defect of sticking up or surface is tiny; For cut deal, will make surface of steel plate form the defects such as bulge, every mechanical performance index of severe exacerbation steel.

The key of eliminating finished product material surface imperfection is exactly will be with effective caustic solution in the steel billet check, the order of severity of rimhole in abundant reproducing steel billet truly.The handshake result, control smelting process in time, guarantees that air blister defect does not flow into rolling process.

At present, usually adopt the erosion of low power hot acid, sulphur print to detect the macro defects such as rimhole of steel billet.Chemico-analytic Determination of octafluoropropane content result is as auxiliary reference.The hot aciding corrosive power of low power is strong, major defect is exposed fully, but rimhole is generally less defect, and after being subject to deep-etching, its pattern is often destroyed or obscure mutually with the macrostructure form, and indistinguishable, cause undetected.Sulphur print is based on the existence that in steel, the segregation effect of element sulphur sets off by contrast air blister defect.Generally, in the subcutaneous base shell of steel billet zone, the sulphur segregation is similar to 0, so the air blister defect at this place can't show at all.The chemical gas analytic approach can only provide the total content of gas, and the distribution of gas in steel billet can not be described, the diagnosis of rimhole defect is not had to direct reference significance.Owing to lacking effective corrosion means, make in steel billet air blister defect can't be correctly, effectively, reflect truly, while causing the steel billet bubble serious, can not feed back in time, make a large amount of air blister defects be brought into rolling process, cause rejection rate to raise.

Summary of the invention

The present invention aims to provide a kind of easy and simple to handle, and check speed is fast, but original appearance shows steel billet rimhole defect distribution and form, improves the degree of accuracy of check, and to the selective corrosion of steel matrix not strong mordant and compound method thereof.

For this reason, the solution that the present invention takes is:

A kind of mordant that shows the steel billet rimhole, is characterized in that, the composition of every part of mordant consists of:

Ferric trichloride 10～25g, absolute ethyl alcohol 50～100 ml, nitric acid 4～6 ml, hydrochloric acid 15～30 ml, cupric chloride 0.8～1.0g, distilled water 1500～2000 ml.

A kind of mordant compound method that shows the steel billet rimhole, is characterized in that, concrete grammar is:

The ferric trichloride solid chemicals of ormal weight is placed in to a glass container, adds distilled water 1500～2000 ml, the ferric trichloride solid chemicals is dissolved;

The absolute ethyl alcohol of getting ormal weight joins in ferric chloride aqueous solutions, after stirring, the nitric acid of ormal weight and hydrochloric acid is added wherein successively;

The cupric chloride medicament that finally adds ormal weight, fully stir, and makes the finished product mordant.

Beneficial effect of the present invention is:

1, original appearance manifests distribution, size and the form of steel billet macrostructure rimhole clearly, thereby improves the recall rate of rimhole defect, avoids undetected phenomenon, reduces the mass loss of subsequent process.

2, because mordant is weak cold acid etching reagent, selective corrosion to steel matrix is not strong, the structure of shown steel matrix is the careful tissue of dendrite, does not disturb, destroys the rimhole pattern, makes the edge clear of this reduced size gross imperfection of rimhole.

3, have check speed fast, pollute littlely, save the energy, the characteristics such as easy and simple to handle, solved by hot acid or other cold acid etching methods and can not show the difficult problem of steel billet rimhole defect clear, comprehensively.

Embodiment

Embodiment 1:

For showing containing C 0.095 wt%, Si 0.01 wt%, Mn 0.34 wt%, P 0.011 wt%, S 0.0052 wt%, Cr 0.03 wt%, Ni 0.005 wt%, Ti 0.005 wt%, the low alloy steel strand rimhole defect form that surplus is Fe.

Get 12 gram ferric trichloride solid chemicals and be placed in a glass container, add 2000 milliliters of distilled water that the ferric trichloride solid chemicals is dissolved.Get 50 milliliters of absolute ethyl alcohols and join in ferric chloride aqueous solutions, add 5 milliliters of nitric acid after stirring, stir, then add 15 milliliters of hydrochloric acid, then stir.Finally add 0.8 gram cupric chloride medicament, fully stir and dissolve, complete the preparation of mordant.

Before detection, first steel billet xsect specimen surface is processed into to the examination face that roughness is Ra≤0.025 μ m.

Dip in the even wiping specimen surface of corrosion liquid with absorbent cotton again, corrode 5 minutes, when the dendritic morphology wait the examination face of being observed visually matrix presents, shows simultaneously dark circles spot shape rimhole defect, uniform corrosion is 1 minute again, until rimhole circle spot size, stablize when constant, to examination face upper punch hot water or cold water, dry up immediately.

Corrosive effect: original appearance has manifested distribution, size, the form of steel billet macrostructure rimhole clearly.Embodiment 2:

For showing containing C 0.09 wt%, Si 0.26 wt%, Mn 0.21 wt%, P 0.104 wt%, S 0.003 wt%, the continuous casting steel billet rimhole defect form that surplus is Fe.

Get 10 gram ferric trichloride solid chemicals and be placed in a glass container, add 2000 milliliters of distilled water by solid

Medicament dissolves.Get 60 milliliters of absolute ethyl alcohols and join in ferric chloride aqueous solutions, add 5 milliliters of nitric acid after stirring, stir, then add 20 milliliters of hydrochloric acid, then stir.Finally add 0.9 gram cupric chloride medicament, fully stir, complete the preparation of mordant.

Before detection, steel billet xsect specimen surface is processed into to the examination face that roughness is Ra≤0.025 μ m.Dip in the even wiping specimen surface of corrosion liquid with absorbent cotton again, corrode 5 minutes, wait the dendritic morphology appearance of the examination face of being observed visually matrix, while presenting dark circles spot shape rimhole defect simultaneously, uniform corrosion is 1 minute again, until rimhole circle spot size, stablize when constant, to examination face upper punch hot water or cold water, dry up immediately.

Corrosive effect: original appearance has manifested distribution, size, the form of steel billet macrostructure rimhole clearly.

Embodiment 3:

For showing containing C 0.12 wt%, Si 0.16 wt%, Mn 1.5 wt%, P 0.012 wt%, S 0.001 wt%, Ca 0.0019 wt%, N 0.0029 wt%, the continuous casting steel billet rimhole defect form that surplus is Fe.

Get 25 gram ferric trichloride solid chemicals and be placed in a glass container, add 2000 milliliters of distilled water that solid chemicals is dissolved.Get 100 milliliters of absolute ethyl alcohols and join in ferric chloride aqueous solutions, add 6 milliliters of nitric acid after stirring, stir, then add 30 milliliters of hydrochloric acid, then stir.Finally add 1.0 gram cupric chloride medicaments, fully stir, complete the preparation of mordant.

Before detection, first steel billet xsect specimen surface is processed into to the examination face that roughness is Ra≤0.025 μ m; Dip in the even wiping specimen surface of corrosion liquid with absorbent cotton again, corrode 3 minutes, wait the dendritic morphology of the examination face of being observed visually matrix, while observing dark circles spot shape rimhole defect simultaneously, uniform corrosion is 1 minute again, until rimhole circle spot size, stablize when constant, to examination face upper punch hot water or cold water, dry up immediately.

Corrosive effect: original appearance has manifested distribution, size, the form of steel billet macrostructure rimhole clearly.

Claims (2)

1. a mordant that shows the steel billet rimhole, is characterized in that, the composition of every part of mordant consists of:

Ferric trichloride 10～25g, absolute ethyl alcohol 50～100 ml, nitric acid 4～6 ml, hydrochloric acid 15～30 ml, cupric chloride 0.8～1.0g, distilled water 1500～2000 ml.

2. a mordant compound method that shows as claimed in claim 1 the steel billet rimhole, is characterized in that, concrete grammar is:

The ferric trichloride solid chemicals of ormal weight is placed in to a glass container, adds distilled water 1500～2000 ml, the ferric trichloride solid chemicals is dissolved;

The absolute ethyl alcohol of getting ormal weight joins in ferric chloride aqueous solutions, after stirring, the nitric acid of ormal weight and hydrochloric acid is added wherein successively;

The cupric chloride medicament that finally adds ormal weight, fully stir, and makes the finished product mordant.