GB1572472A

GB1572472A - Method of joining cast iron parts to one another or to steel parts

Info

Publication number: GB1572472A
Application number: GB1647377A
Authority: GB
Original assignee: VACUUM SOLDIER CT VOF
Current assignee: VACUUM SOLDIER CT VOF
Priority date: 1976-04-20
Filing date: 1977-04-20
Publication date: 1980-07-30
Also published as: FR2348782B1; DE2716975C3; CH620385A5; FR2348782A1; IT1081350B; BE853628A; NL7604170A; DE2716975A1; DE2716975B2

Abstract

For joining cast iron grades to one another or to steel grades, the components are heated in a furnace in vacuo to a temperature of between 800 DEG C and 1350 DEG C, and a soldering material is used which contains at least 50 per cent by weight of copper. In this way, a high-quality joint is obtained, the method also being suitable for mass production.

Description

(54) METHOD OF JOINING CAST IRON PARTS TO ONE ANOTHER OR TO STEEL PARTS (71) We, VACUUM SOLDEER CEN TRUM v.o.f., of Oostenburgermiddenstraat 62, Amsterdam, the Netherlands, 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 particularly described in and by the following statement: The invention relates to a method of joining cast iron parts to one another or to parts of steel. Hitherto no high grade method of connecting different kinds of cast iron to one another or to various kinds of steel has become known for use in a series and mass production. The invention has for its object to provide a method of joining such parts, which is suitable for being carried out in series and mass production.

According to the invention the parts are brazed with the aid of a material containing at least 50% of copper the brazing operation being carried out in a furnace at a pressure lying between 10-4Torr and 100 Torr and at a temperature between 800"C and 13500C.

Such a method provides a very high-grade joint between the various parts. The properties of the joints are substantially equal to or even better than those of the materials to be joined. The method described is suitable for brazing all kinds of cast iron, for example, ferritic, ferritic, pearlitic, and/or austenitic cast iron, non-alloy, low-alloy and/or highalloy cast iron, cast iron of laminar structure, of nodular structure and/or of intermediate mixed structure, which types of cast iron can be connected with one another and/or with material of some kind of steel. Since heating is performed in a furnace, uniform heating on all sides is ensured so that deformation of the parts to be joined will not occur. Even connections at places very difficult of access and connections of parts having highly different cross-sections can be established.

According to the invention the parts to be joined can be accurately fixed in their relative places before being inserted into the furnace and the brazing material can be disposed in the neighbourhood of the seam to be made in the form of a wire, a foil or a powder or in a form derived therefrom.

According to a preferred embodiment of the invention, after the parts to be joined are inserted into the furnace, the furnace is evacuated for 15 minutes to achieve the desired pressure, after which the temperature in the furnace is raised to the desired value to effect brazing; then cooling is performed, if necessary forcibly, to below 1500C by admitting an inert gas into the furnace.

The methods described above do not require the use of a flux so that there is no risk of places not being contacted by braze due to the presence of an excessive quantity of flux.

The brazed objects are quite clean after the brazing operation so that subsequent cleaning is not required.

WHAT WE CLAIM IS: 1. A method of joining cast iron parts to one another or to parts of steel characterised in that the parts are brazed with the aid of a material containing at least 50% of copper, the brazing operation being carried out in a furnace at a pressure lying between lO-4Torr and 100 Torr and at a temperature between 8000 and 13500C.

2. A method as claimed in claim 1, characterised in that prior to introduction into the furnace, the parts to be joined are accurately fixed in their relative places and in that the soldering material is disposed in the neighbourhood of the seam to be made in the form of wire, foil or powder or in a form derived therefrom.

3. A method as claimed in claim 1 or claim 2, characterised in that after the parts to be joined are inserted into the furnace, the furnace is first exhausted to the desired pressure, after which the temperature in the furnace is raised to the desired value and cooling is subsequently performed, if necessary in a forced manner, to below 1500C, an inert gas being admitted into the furnace.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. (54) METHOD OF JOINING CAST IRON PARTS TO ONE ANOTHER OR TO STEEL PARTS (71) We, VACUUM SOLDEER CEN TRUM v.o.f., of Oostenburgermiddenstraat 62, Amsterdam, the Netherlands, 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 particularly described in and by the following statement: The invention relates to a method of joining cast iron parts to one another or to parts of steel. Hitherto no high grade method of connecting different kinds of cast iron to one another or to various kinds of steel has become known for use in a series and mass production. The invention has for its object to provide a method of joining such parts, which is suitable for being carried out in series and mass production. According to the invention the parts are brazed with the aid of a material containing at least 50% of copper the brazing operation being carried out in a furnace at a pressure lying between 10-4Torr and 100 Torr and at a temperature between 800"C and 13500C. Such a method provides a very high-grade joint between the various parts. The properties of the joints are substantially equal to or even better than those of the materials to be joined. The method described is suitable for brazing all kinds of cast iron, for example, ferritic, ferritic, pearlitic, and/or austenitic cast iron, non-alloy, low-alloy and/or highalloy cast iron, cast iron of laminar structure, of nodular structure and/or of intermediate mixed structure, which types of cast iron can be connected with one another and/or with material of some kind of steel. Since heating is performed in a furnace, uniform heating on all sides is ensured so that deformation of the parts to be joined will not occur. Even connections at places very difficult of access and connections of parts having highly different cross-sections can be established. According to the invention the parts to be joined can be accurately fixed in their relative places before being inserted into the furnace and the brazing material can be disposed in the neighbourhood of the seam to be made in the form of a wire, a foil or a powder or in a form derived therefrom. According to a preferred embodiment of the invention, after the parts to be joined are inserted into the furnace, the furnace is evacuated for 15 minutes to achieve the desired pressure, after which the temperature in the furnace is raised to the desired value to effect brazing; then cooling is performed, if necessary forcibly, to below 1500C by admitting an inert gas into the furnace. The methods described above do not require the use of a flux so that there is no risk of places not being contacted by braze due to the presence of an excessive quantity of flux. The brazed objects are quite clean after the brazing operation so that subsequent cleaning is not required. WHAT WE CLAIM IS:

1. A method of joining cast iron parts to one another or to parts of steel characterised in that the parts are brazed with the aid of a material containing at least 50% of copper, the brazing operation being carried out in a furnace at a pressure lying between lO-4Torr and 100 Torr and at a temperature between 8000 and 13500C.

4. A method as claimed in claim 1 conducted substantially as described herein.

5. An object comprising parts joined by a method as defined in any one of the preceding claims, characterised in that between the parts a brazed seam is formed with the aid of a material containing at least 50% of copper.