GB1579952A - Molten metal sampling - Google Patents

Description

(54) AN IMPROVEMENT IN OR RELATING TO MOLTEN METAL SAMPLING (71) We, THE AMALGAMS COMPANY LIMITED, a British Company, of Tinsley Park Road, Sheffield 9, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particu larly described in and by the following statement:- The invention relates to molten metal sampling and has for its object to provide an improvement therein.

When taking samples of molten steel for hydrogen analysis it is important for the samples to be quenched very quickly so that the hydrogen content of the sample is not lost to the atmosphere. The invention aims to facilitate this.

According to one aspect of the invention a method of taking a sample of molten steel for hydrogen analysis includes the steps of temporarily securing the neck of a longitudinally split metal mould in an aperture in a resilient plug, entering the plug into one end of a tubular sheath so that the metal mould is contained therein; fitting a silica tube in the neck of the metal mould through the aperture in the resilient plug; holding the end of the silica tube remote from the plug in a stream of molten steel so that a cavity within the metal mould is filled with a sample of the steel; and imparting a sharp blow to the tubular sheath so that the neck of the mould is detached from the resilient plug, whereby the mould is able to fall apart and the sample is able to fall out from within the mould to fall through the open end of the tubular sheath into a container of water in which it is quickly quenched.

The method may include the further step of fitting a band of a combustible material around the metal mould remote from the neck so that the mould is held together until a sample of molten steel is received in the mould cavity. The method may include the step of mounting the tubular sheath on a so-called lance for the purpose of holding the silica tube in a stream of molten metal.

When the sample has been quenched so that it can be handled, it may be frozen in ice until required for analysis.

According to another aspect of the invention, a device for sampling molten steel for hydrogen analysis is constituted by a longitudinally split metal mould located within a card-board sheath by a resilient plug surrounding an end portion of a neck of the mould, a part of the mould remote from the neck being held together by a combustible band, the arrangement being such that when a sample of molten steel has been received in the mould and the heat of the sample has destroyed the combustible band holding the mould together, a sharp blow on the edge of a water bucket by the cardboard sheath causes the metal mould to be detached from the resilient plug and to fall apart so that the sample can fall through the open end of the sheath remote from the plug into the water, separately from the halves of the mould.A silica tube will preferably extend from the neck of the metal mould so that it can be held in a stream of molten steel being poured.

In order that the invention may be fully understood and readily carried into effect, the same will now be described, by way of example only, with reference to the drawings the Provisional Specification, of which: Fig. 1 is a sectional view of a device embodying the invention for sampling molten steel, Fig. 2 is a perspective view of a part of the device which will be referred to, and Fig. 3 is a view which illustrates the elements shown in Fig. 2, together with a steel sample which has been formed therein, being dropped into a water bucket for the quenching of the sample.

Referring now to Fig. 1 of the drawings, the device there illustrated for sampling molten steel includes a metal mould generally indicated 10 which is longitudinally split so that it is constituted by two separate parts 12 and 14. When placed together as shown in Fig. 1 the parts of the mould define a cylindrical cavity. At one end the mould is provided with a cylindrical neck portion 16 and at its other end with a local depression 18 in the joint face of at least one of its two parts which forms a small hole for the escape of gas from the mould cavity.

The metal mould 10 is located within a cardboard sheath 20 by means of a resilient plug 22 which has been push fitted in one end of said sheath. The neck of the metal mould has been entered a short distance into a central aperture 24 in the plug, and a part of the mould remote from the neck is shown to be held together by a combustible band 26 (a thin band of cardboard). A silica tube 28 extends from the neck of the metal mould so that it can be held in a stream of molten steel being poured from a ladle. The end of the cardboard sheath remote from the resilient plug is open and the arrangement is such that, as shown in chain-dotted lines in Fig. 1, the sheath containing the mould can be located on a so-called cup 30, that is to say an open ended tapering member secured at one end of a lance 32, and the silica tube can be held, as shown, in the stream of molten steel.

When a sample of molten steel has been received in the mould cavity, the cardboard sheath can be removed from the lance and a sharp blow on the edge of a water bucket 34 by the cardboard sheath then causes the metal mould to be detached from the resilient plug and to fall into the water. Since the heat of the sample will by this time have destroyed the combustible band 26 holding the mould together, the mould will fall apart as it becomes detached from the resilient plug and, as shown in Fig. 3, the sample will fall through the open end of the sheath into the water separately from the halves of the mould. Consequently the steel sample is immediately quenched as it falls into the water. When the sample has been quenched so that it can be handled it may be frozen in ice until required for analysis.It has been found that a steel sample taken in this way gives a more accurate analysis of the hydrogen content of the steel than has been possible when using conventional methods and devices for taking samples of molten steel.

Various modifications may be made without departing form the scope of the invention and it will be understood for example that the halves of the metal mould may be made of steel or of copper or indeed that they may be of sintered form. It will also be understood that the degree with which the neck of the metal mould should be forced into the central aperture in the resilient plug so that it is held securely enough for taking the sample of metal but loosely enough to ensure that it can be shaken out without difficulty by a single sharp blow of the cardboard sheath against a water bucket will quickly determined by a person taking the samples.

WHAT WE CLAIM IS: 1. A method of taking a sample of molten steel for hydrogen analysis, the method including the steps of temporarily securing the neck of a longitudinally split metal mould in an aperture in a resilient plug, entering the plug into one end of a tubular sheath so that the metal mould is contained therein; fitting a silica tube in the neck of the metal mould through the aperture in the resilient plug; holding the end of the silica tube remote from the plug in a stream of molten steel so that a cavity within the metal mould is filled with a sample of the steel; and imparting a sharp blow to the tubular sheath so that the neck of the mould is detached from the resilient plug; whereby the mould is able to fall apart and the sample is able to fall out from within the mould to fall through the open end of the tubular sheath into a container of water in which it is quickly quenched.

2. A method of taking a sample of molten steel for hydrogen analysis according to calim 1 the method including the further step of fitting a band of a combustible material around the metal mould remote from the neck so that the mould is held together thereby until a sample of molten steel is received in the mould cavity.

3. A method of taking a sample of molten steel for hydrogen analysis according to either one of the preceding claims, the method including the step of mounting the tubular sheath on a so-called lance for the purpose of holding the silica tube in a stream of molten metal.

4. A method of taking a sample of molten steel for hydrogen analysis according to any one of the preceding claims, in which when the sample has been quenched so that it can be handled, it is frozen in ice until required for analysis.

5. A device for sampling molten steel for hydrogen analysis, said device being constituted by a longitudinally split metal mould located within a cardboard sheath by a resilient plug surrounding an end portion of a neck of the mould, a part of the mould remote from the neck being held together by a combustible band, the arrangement being such that when a sample of molten steel has been received in the mould and the heat of the sample has destroyed the combustible band holding the mould together, a sharp blow on the edge of a water bucket or the like by the cardboard sheath causes the metal mould to be detached from the resilient plug and to fall apart so that the sample can fall through the open end of the sheath remote from the plug into the water, separately from the halves of the mould.

6. A device sampling molten steel for hydrogen analysis according to claim 5, in which a silica tube extends from the neck of the metal mold so that it can be held in a stream of molten steel being poured.

7. A method of taking a sample of molten steel for hydrogen analysis, substantially as hereinbefore described with reference

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (8)

**WARNING** start of CLMS field may overlap end of DESC **. The metal mould 10 is located within a cardboard sheath 20 by means of a resilient plug 22 which has been push fitted in one end of said sheath. The neck of the metal mould has been entered a short distance into a central aperture 24 in the plug, and a part of the mould remote from the neck is shown to be held together by a combustible band 26 (a thin band of cardboard). A silica tube 28 extends from the neck of the metal mould so that it can be held in a stream of molten steel being poured from a ladle. The end of the cardboard sheath remote from the resilient plug is open and the arrangement is such that, as shown in chain-dotted lines in Fig. 1, the sheath containing the mould can be located on a so-called cup 30, that is to say an open ended tapering member secured at one end of a lance 32, and the silica tube can be held, as shown, in the stream of molten steel. When a sample of molten steel has been received in the mould cavity, the cardboard sheath can be removed from the lance and a sharp blow on the edge of a water bucket 34 by the cardboard sheath then causes the metal mould to be detached from the resilient plug and to fall into the water. Since the heat of the sample will by this time have destroyed the combustible band 26 holding the mould together, the mould will fall apart as it becomes detached from the resilient plug and, as shown in Fig. 3, the sample will fall through the open end of the sheath into the water separately from the halves of the mould. Consequently the steel sample is immediately quenched as it falls into the water. When the sample has been quenched so that it can be handled it may be frozen in ice until required for analysis.It has been found that a steel sample taken in this way gives a more accurate analysis of the hydrogen content of the steel than has been possible when using conventional methods and devices for taking samples of molten steel. Various modifications may be made without departing form the scope of the invention and it will be understood for example that the halves of the metal mould may be made of steel or of copper or indeed that they may be of sintered form. It will also be understood that the degree with which the neck of the metal mould should be forced into the central aperture in the resilient plug so that it is held securely enough for taking the sample of metal but loosely enough to ensure that it can be shaken out without difficulty by a single sharp blow of the cardboard sheath against a water bucket will quickly determined by a person taking the samples. WHAT WE CLAIM IS:

1. A method of taking a sample of molten steel for hydrogen analysis, the method including the steps of temporarily securing the neck of a longitudinally split metal mould in an aperture in a resilient plug, entering the plug into one end of a tubular sheath so that the metal mould is contained therein; fitting a silica tube in the neck of the metal mould through the aperture in the resilient plug; holding the end of the silica tube remote from the plug in a stream of molten steel so that a cavity within the metal mould is filled with a sample of the steel; and imparting a sharp blow to the tubular sheath so that the neck of the mould is detached from the resilient plug; whereby the mould is able to fall apart and the sample is able to fall out from within the mould to fall through the open end of the tubular sheath into a container of water in which it is quickly quenched.

2. A method of taking a sample of molten steel for hydrogen analysis according to calim 1 the method including the further step of fitting a band of a combustible material around the metal mould remote from the neck so that the mould is held together thereby until a sample of molten steel is received in the mould cavity.

3. A method of taking a sample of molten steel for hydrogen analysis according to either one of the preceding claims, the method including the step of mounting the tubular sheath on a so-called lance for the purpose of holding the silica tube in a stream of molten metal.

4. A method of taking a sample of molten steel for hydrogen analysis according to any one of the preceding claims, in which when the sample has been quenched so that it can be handled, it is frozen in ice until required for analysis.

5. A device for sampling molten steel for hydrogen analysis, said device being constituted by a longitudinally split metal mould located within a cardboard sheath by a resilient plug surrounding an end portion of a neck of the mould, a part of the mould remote from the neck being held together by a combustible band, the arrangement being such that when a sample of molten steel has been received in the mould and the heat of the sample has destroyed the combustible band holding the mould together, a sharp blow on the edge of a water bucket or the like by the cardboard sheath causes the metal mould to be detached from the resilient plug and to fall apart so that the sample can fall through the open end of the sheath remote from the plug into the water, separately from the halves of the mould.

6. A device sampling molten steel for hydrogen analysis according to claim 5, in which a silica tube extends from the neck of the metal mold so that it can be held in a stream of molten steel being poured.

7. A method of taking a sample of molten steel for hydrogen analysis, substantially as hereinbefore described with reference

to and as illustrated by the drawings accompanying the Provisional Specification.

8. A device for sampling molten steel for hydrogen analysis, substantially as hereinbefore described with reference to and as illustrated by the drawings accompanying the Provisional Specification.