books



previous page: Notes On Construction In Mild Steel | by Henry Fidler
  
page up: Metalwork Books
  
next page: Do It Yourself With Aluminum. 125 Projects For The Home Craftsman | by Author: G. W. Birdsall

Welding Theory, Practice, Apparatus And Tests Electric, Thermit And Hot-Flame Processes | by Richard N. Hart



In spite of the numerous data on the theory, practice, apparatus, and tests of welding contained in the trade journals and metallurgical books, no previous attempt has been made to present this data in sequence under one cover. But in the last fifteen years the subject has begun to be of interest and importance. The electric, thermit, and hot-flame processes are welding all of the metals and are doing repeat and repair work that has never before been attempted. New brazing methods have also been successfully tried out and the range of good solders greatly increased.

TitleWelding Theory, Practice, Apparatus And Tests Electric, Thermit And Hot-Flame Processes
AuthorRichard N. Hart
PublisherThe McGraw-Hill Book Company
Year1910
Copyright1910, The McGraw-Hill Book Company
AmazonWelding: Theory, Practice, Apparatus And Tests, Electric, Thermit And Hot-Flame Processes

By Richard N. Hart, B. S

-Preface
In spite of the numerous data on the theory, practice, apparatus, and tests of welding contained in the trade journals and metallurgical books, no previous attempt has been made to present this data i...
-Definitions And Introduction
According to the Standard Dictionary, to weld is to unite, as heated metal, in one piece or mass under the hammer or by pressure. The Century Dictionary says, To unite or consolidate, as pieces of...
-Theories Of Welding
In 1877, Holley1 advanced the theory that irons weld in proportion to their mobility or flowing, and inversely as oxidation of the welding surfaces occurs. He thought that the more plastic or more nea...
-Welding. Part I. The Metals Iron
Pure or nearly pure iron is readily weldable at a white heat. Malleable, or nearly pure wrought iron, is known as weld iron. The range of temperature in which it can be welded is very wide: it runs fr...
-Malleable Iron
Weld iron is a name occasionally used to describe malleable iron, indicating that it is pure enough to be welded. Malleable iron is produced by the puddling process. It is made by melting up pig iron ...
-How To Weld Iron
The mechanics of a smithed weld is in the main as follows: Suppose the smith wishes to join two short bars of malleable iron, of cross-section 1 by 2 inches. He first hammers or cuts a convex bevel ...
-Points In Practice
In practice there are the usual number of details requiring skill that the smith must observe. The contact faces should always be shaped so that their middle points touch first and so that hammering ...
-Welding Fires, Etc
The ordinary fire used by the smith for his welding is a deep bed of coke. But the fire may be fed with hard or soft coal; it may also be a gas or oil flame. Fig. 5. - Jump weld. Fig. 6. - Butt ...
-Causes Of Poor Welds
Suppose we have an iron or steel that will weld. There are still many good reasons for discrediting the safety of the joint until it has been tested. They are: 1. Imperfect Contact. a. The two surfa...
-Iron I
It cannot, therefore, be welded over the smith's forge, and can be welded only by one of the recent special processes. There are an infinite number of kinds of iron, due to the proportions of the com...
-Iron II
Nickel steel welds readily at all compositions. Nickel is a valuable addition to iron, because small percentages of it greatly increase the tensile strength without impairing the elasticity. It is als...
-Iron II. Continued
Welds made with steam hammer were 10 per cent, stronger for mild steel and 5 per cent, stronger for wrought iron on the average than hand welds. Results Of Tests By W. C. Unwin1 Percentage of ...
-Platinum
Though a rare metal, being at this writing more expensive than gold, platinum is much used for analytical apparatus. Between the years 1827-44 it was used by the Russian government for coinage.3 But i...
-Gold
Gold is the most easily weldable of all the metals. Like lead, it can be welded cold and, provided it is free from certain impurities, it can be joined at all temperatures. Gold is generally placed fi...
-Silver
Silver is also a metal of history. The ancient Greeks knew of it as the metal electrum, an alloy of gold and silver, of a brilliant pink-whiteness. Silver is now used largely as a silver-gold or silve...
-Aluminum
Aluminum is one of the youngest of the metals. It was discovered by Wcehler in 1827. At first its considerable expense prevented its being generally used. About 1889, however, the discovery of new pro...
-Copper
Copper is one of the oldest, if not the very oldest, metals of history. It was used almost entirely as an alloy with tin or zinc, until recent times. The aborigines of North America, however, found th...
-Nickel
Nickel is a metal of secondary importance. Its principal use is in nickel alloys, notably nickel-steel, in plating, in coinage, and in the chemical reductions which call for apparatus made of a metal ...
-Welded Products
A great variety of tools, appliances, and parts are welded in some stage of their manufacture. Where pieces of metal are to be joined, welding is the first resort, soldering a poor alternative. As wel...
-Wrought-Iron Pipe
Pipe welding is about 100 years old, and at this writing the manufacture of welded wrought-iron pipe consumes a large percentage of all the wrought iron made. The first pipe was heated over a coke fir...
-Chain Making
Chains made of iron links were known to the first smiths or workers in iron. And though chain is now replaced in many instances by lighter and stronger cables, it is one of the staple iron and steel p...
-Part II. Electric Welding
General Electric welding processes have been used commercially since about 1880, when Elihu Thomson brought out his low-pressure resistance machine, invented about 1877. In recent years several proce...
-The La Grange-Hoho Process
This process is well called the water-pail forge. It comes from Belgium and has scarcely been tried out. The metals to be heated are fastened to the negative pole of the circuit and immersed in a ba...
-The Zerener Electric Blowpipe
Werderman applied the high heat of the electric arc to melting and welding metals. His apparatus was an ordinary flaming arc, the carbons being inclined toward each other. The flame of the arc was dir...
-The Bernardos Arc-Welding Process
This arc-welding process is an evolution of the electric furnace. In the electric furnace of Moissan and others the electrodes were both carbon, and the metal to be melted was placed between the carbo...
-Apparatus And Current. - The Generator
It is claimed by the advocates of this system that good results cannot be obtained unless current of ample volume and pressure be used. Current from power wires is generally inadequate. It is best to ...
-Table, Switches, Controlling Apparatus, Carbon
The table which holds the work is of cast or wrought iron. The metal to be welded is laid on the table, and it is supposed that the contact between table and metal will be sufficient to carry the curr...
-Workman's Protective Apparatus
Under this head come rubber gloves, a leather or rubber suit or apron, a hood of cloth, stovepipe or wood for the head, and a pair of glasses for the eyes. Bear in mind that the operator is manipulati...
-Cutting Metals With Electric Arc
The Bernardos arc is also used to cut metals. Its adaptation to metal cutting is of recent date. The arc is held stationary over the plate until the metal is melted in one place. This melted metal is ...
-The Thomson Process
This process differs radically from all the others in forcing through the metal to be heated electrically such volumes of current that its own resistance is sufficient to bring every molecule of the ...
-The Transformer
Current from a lighting circuit of 54 or 104 volts can be carried directly to the welding clamps without being transformed. Such a welder is called a direct welder, and is used for small work only. Wi...
-Regulating Apparatus
Regulating apparatus includes a switch-board on which are assembled a reactive coil, rheostat, potential indicator, and fuse blocks and switches; and apparatus for automatically shutting off the curre...
-The Clamps
The clamps vary in design in different types of machines. Figures 16 and 19 show clamps for various work. They are generally of heavy copper, to allow for the passage of the large volume of current. T...
-The Clamps. Part 2
When full range of sizes is to be welded or when the smaller sizes only are to be welded, a current controller is furnished with the welder. Energy Absorbed In Electric Welding - Prof. Thomson's Proc...
-The Clamps. Part 3
Prof. Thomson has in his possession a metal bar of 3/8-inch diameter which is made of nine different metals welded together. However, the Thomson Company does not recommend its machine for cast iron o...
-The Clamps. Part 4
Rail welding was first suggested by Thomson and practised with one of his machines. On account of the importance of electric rail welding and the special apparatus needed, the process will be describe...
-Locomotive Flue Welder
The Warren Electric Manufacturing Company has furnished the following description of their flue welder, which is especially adapted to the work: The flue welder (Fig. 30) operates from an alternatin...
-Rail Welding By The Thomson Process
The most important single application of the Thomson process has been to the welding of street-car rails. Before 1892, all rail welding was done by the cast-welding process. Cast-welding is briefly as...
-Electric Resistance Heater
Besides its use as a welder, the machine may be used as a preheater of metals to be brazed or bent. It will sometimes be preferable to braze or solder a joint, when the two metals cannot be allowed to...
-The Oxy-Acetylene Process
General Lest the variations in practice and the variety of apparatus about to be described should prove confusing, it is well to state that the oxy-acetylene welding process depends on the high heat ...
-Apparatus And Gases. - The Torch
The first oxy-acetylene torch was invented by Mr. Edmond Fouche, who at the time was general manager of the Campagnie Francaise de P Acetylene dissous. As they were using compressed acetylene in acet...
-Miscellaneous Apparatus
Besides the apparatus already touched on, there are pressure-reducing valves on all of the pressure tanks. These may be set by the turning of a handle to any constant pressure required; the dial shows...
-Electrolysis Of Water
When water is decomposed by electrolysis, it gives 2 volumes hydrogen, 1 volume oxygen. The electrolyte is a dilute solution of sodium or potassium hy-droxid; oxygen rises from the positive and hydro...
-Storage Oxygen
Oxygen can be bought in steel cylinders. There are two industrial processes at present for making oxygen. It can be drawn from the atmosphere by the liquid-air method or it can be produced by the elec...
-Oxygenite
Oxygenite is the name given to the oxygen-producing powder sold by the Industrial Oxygen Co. Its main constituents are potassium chlorate and manganese dioxid in the probable proportion of 100 to 13...
-Oxygen From Chlorate
The Davis-Bournonville Company has recently added to its line apparatus for the production of oxygen. The method is similar to the Oxygenite process, but the oxygen mixture is not combustible; it must...
-Oxone
Very pure oxygen can be generated on a small scale by wetting sodium peroxid. 4NaO+2H2O = 4NaOH + O2. The Oxone idea is a recent development of an old method. The sodium peroxid in fused lumps is de...
-Acetylene
Acetylene is a heavy, combustible gas with a strong odor, and was first made by Davy in 1837. It is produced by the reaction between water and calcium carbid according to the formula CaC2+H2O = C2H2+C...
-The Acetylene Generator
In repair shops, Where acetylene will be needed continually for the work at hand, it is best to install an acetylene generator. One of the types approved by the underwriters should be selected. It sho...
-Dissolved Acetylene
Acetylene dissociates at 780 deg. Cent, into carbon and hydrogen; under pressure of two atmospheres or more, the gas is tricky and is liable to explode. But acetylene is readily soluble in a number of...
-The Flame
The flame is lighted by first turning on the acetylene, lighting it, and then turning on the oxygen. The acetylene burns with a bright, smoky flame. As the oxygen jet increases, an indefinite-shaped c...
-How To Weld
To weld, the operator goes over the metal quickly with the flame a number of times. This will heat the metal evenly to about dull red heat. If the work is stock work and is continuous, it will save fr...
-Typical Welds And Repairs
The following instances of boiler repair are given by L. L. Bernier, in his Autogenous Welding of Metals: Repairing Cracks Steamer 'Eugene Pereire' of the French Line: The boiler furnaces of the...
-Acetylene Welding Versus Riveting
The approximate strength of single-riveted boiler plate is 55 per cent.; of double-riveted, 70 per cent. L. L. Bernier, in the Boiler Maker, gives the ratio of cost of acetylene welding with a generat...
-Repairing Defective Castings
One of the important possibilities of this process is in the repairing of defective castings fresh from the foundry. Even in the most careful foundry practice the scrap heap is always a very expensive...
-How To Cut Metals
Besides its use in melting metals for welding, it has recently been found that the oxy-acetylene flame will cut through metals. The importance of this discovery is not yet realized. Wrought-iron and s...
-Welding Costs
It is, of course, impossible to give costs in an empirical way. In the first place, improved methods of generating the two gases are still being advanced, as well as improved apparatus for production ...
-Chemistry And Thermics
A definite formula should not be laid down for the oxy-acetylene flame as used. This for the reason that the products of combustion vary with different proportions of the gases and in different parts ...
-The Oxy-Hydrogen Process
General The oxy-hydrogen flame is the first, historically, of the high-temperature flames. It was used long before the discovery of industrial electrolysis of water or the production of oxygen by liq...
-The Thermit Process
General One of the most recent and successful methods of welding is called the Thermit Process. It was invented by Dr. Goldschmidt, of Essen, Germany, and is exploited by the company bearing his name...
-Apparatus And Rail Welding
Suppose a case of two rails abutting which are to be welded together. It is a railway crossing where heavy trains pound. The weld must be at least as strong as the rail. It must be so made as not to i...
-The Crucible
With the exception of butt-welding, where an ordinary hot crucible is used, the crucible for all thermit-welding is a cone-shaped affair that taps at the bottom. It is an evolution of the thermit proc...
-The Mold
Molds for thermit work are adapted to the particular joint to be made. For welding a number of joints of uniform size the company furnishes patterns with which the operator can make his own molds, or ...
-The Mold. Continued
There are a number of instances where the shoulder must be machined off, though the weld must be as strong as the rest of the piece, as in the case of rails, bearings, etc. Most welds permit of as la...
-Safe-Guarding The Mold
Bear in mind that liquid thermit is exceedingly fluid - as much so as warm molasses - and as it is much heavier, it will search diligently for all openings in the mold. For this reason the mold must b...
-Amount Of Thermit
As has been stated elsewhere, there should be twice as much thermit steel poured for a weld as is necessary to fill the space between the joined pieces and to provide for shoulder around the joint. Th...
-Butt-Welding Of Pipes
One of the unique applications of thermit is in the butt-welding of pipes and bars. It is a very difficult and often impossible thing to make a strong joint of two gas or water pipes without cutting r...
-Mending Defective Castings
Besides its use in welding, thermit is being exploited for the repair of defective castings, which is not strictly a welding operation. Also for raising the temperature of the ladle before pouring for...
-Thermit In Foundry Practice
Thermit may be introduced into the ladle before pouring for a casting. If the piece to be cast is long and thin, or if it has intricate parts which require a very hot metal to produce, the temperature...
-Repair Of The "Betsy Ann"
One of the quickest repairs on record was accomplished on the Mississippi River Steamship ' Betsy Ann/ belonging to Learned & Son, Natchez, Miss. This is a stern wheel boat, the shaft being a hexagon...
-Repair On Steamship "Corunna"
This was a vessel of 1296 tons register, 240 feet long, 35 feet beam and 21 feet depth. In getting away from her pier in the Lachine Canal, Montreal, the stern of the vessel was caught by the current...
-Heat Of Reaction
Richards2 has calculated the heat of the thermit reaction as 2694 deg. Cent. The temperature commonly given by the manufacturers is 3000 deg. Cent. M. Fery, using his new radiation pyrometer, found th...
-Weld Testing
The strength of an ordinary weld in wrought iron varies from 10 to almost 100 per cent, of the strength of an equivalent cross-section of the metal. In general, however, a weld made under proper condi...
-The Lafitte Welding Plate
The Lafitte process was first heard of in 1905.3 It may be described as the handy application of a patent fluxing sheet between parts to be welded, and can only be used for joining iron and steel. The...
-Ferrofix Brazing Process
An ingenious and very good modern method of brazing broken iron parts (especially cast iron) goes by the name of the Ferrofix Brazing Process. It was devised by Frederick Pich, a German. By this proce...
-Brazing And Soldering
Brazing and soldering are processes which are much like welding and which often shade over.into welding. The brazing of brass is welding, except that the metal is not pounded together, but melted. The...
-Brazing
Iron, brass, copper, gold, and silver are the metals joined by brazing. The process is briefly: fluxing the metals at the joint, adding the brazing mixture called spelter, heating until the spelter ...
-Soldering
A solder is a metallic glue. There are almost an infinite number of solders, the most common being lead-tin solder for soldering the common commercial metals. The lead-tin proportion is varied to obta...
-Glossary Of Terms
Burnt Metal If iron or steel is heated to bright white, it will crystallize when cooled. This will make it brittle, and makes the wrongly called burnt iron. To prevent this brittleness the metal must...









TOP
previous page: Notes On Construction In Mild Steel | by Henry Fidler
  
page up: Metalwork Books
  
next page: Do It Yourself With Aluminum. 125 Projects For The Home Craftsman | by Author: G. W. Birdsall