Solder is a material used in soldering to join work pieces and has a melting point lower than the metals to be joined. Alloys based on tin, lead, cadmium, copper, nickel and others are used. There are non-metallic solders. The service life of the solder depends on the correct technology and operating environment. Nowadays, lead free solder wire melting temperature is used commonly.
Soldering is carried out either in order to create a mechanically strong (sometimes tight) seam, or to obtain electrical contact with a low contact resistance. When soldering, the joints are heated. Since the solder has a melting point significantly lower than the metal (or metals) were being joined, it melts while the base metal remains solid.
What is interface between molten solder and solid solder?
At the interface between the molten solder and solid metal, various physical and chemical processes take place. Solder wets the metal, spreads over it and fills the gaps between the parts to be joined. In this case, the components of the solder diffuse into the base metal, the base metal dissolves in the solder, as a result of which an intermediate layer is formed.
What is lead free solder wire melting temperature?
A lead free solder wire melting temperature is selected taking into account the physicochemical properties of the metals to be joined (for example, by the melting temperature), the required mechanical strength of the joint, its corrosion resistance and cost. When soldering live parts, the specific conductivity of the solder must be taken into account.
The fluidity of low-temperature solders makes it possible to solder complex-shaped products. The melting point of soft brazing alloys is up to 300 ° C and has a tensile strength of 16-100 MPa, and hard brazing alloys - 100-500 MPa.
What are lead free solder wire joints and why do we prefer it?
Lap joints are preferred over butt joints. For brazed joints, the minimum overlap is 10 mm for sheet thicknesses up to 3 mm. The joining surfaces of both lead sheets are cleaned and coated with a grease flux. The edge of the bottom sheet should be trimmed 3 mm wider than the top. The edge and outer side of the top sheet should also be trimmed and fluxed at a distance of about 10 mm.
Then the parts are assembled into a knot and tapped with a wooden or rubber-coated hammer for a tight fit. After that, the lead free solder wire melting temperature is tacked with solder in several places at a certain interval. It is often advisable to add additional flux, for example by using rosin-filled or stearic-filled tubular solders.
Brazed joints in the lock have significantly higher strength and are preferred in all cases where the joint is in tension. These joints are made in the same way as overlap joints, with a lock joint with a width of 12.0 mm and more. The solder must flow into the interior of the lock between two contacting surfaces.
Butt joints are the least favorable for soldering lead products. They should only be used in cases where a different type of connection cannot be used. The joint edges of the lead sheets are beveled at an angle of 45 ° or more to the vertical. After that, the prepared edges are joined and seized with a step of 10-15 mm.
Paper strips impregnated with rubber and glued parallel to the edges at a distance of 6 to 10 mm promote the formation of the soldered seam. Lead free solder wire melting temperature is recommended, as for lap joints, to apply an additional amount of flux.
lead free solder wire connection
For good results when brazing pipes, pre-preparation is just as important as the brazing process it. When connecting pipes, one of them is inserted into the flared socket of the pipe into which water or some other liquid is supplied. For a snug fit, the end, entering the pipe socket, is beveled. The contacting surfaces of the joint, as well as the area adjacent to it, are cleaned with scraping.
Why grease impregnated cotton is used?
When brazing pipes horizontally, the junction is slowly poured from above with solder at an appropriate temperature, followed by rubbing. The solder runoff and the formation of the solder seam are regulated manually by the solder gun. For this purpose, grease-impregnated cotton ends are used, with which a paste-like solder is rubbed.
Vertical pipe brazing lead free solder wire
With vertical pipe brazing, the preparation of the joint and the brazing are carried out in the same way as for the horizontal one, except that the lead free solder wire melting temperature is applied around the pipe at the upper border of the brazing zone, and the rubbing ends are held directly under the ladle at the lower border.
Connection of branch pipes
The connection of the branch pipes to the lead pipes is carried out as follows.
- A small oval hole is cut in the lead pipe.
- The edges of the hole are flanged to the required size, forming a bushing,
- a branch pipe with beveled edges is tightly driven
- Further preparation of connection and soldering by rubbing is carried out in the same way as described above
What are the cup pipe connections?
Cup pipe connections are similar to socket-outlet connections, with the only difference that the flared end of the lead pipe is not crimped and soldering is performed mainly with a soldering iron, and not by rubbing. Such connections can only be soldered in an upright position.
Preparation of a joint for lead free solder wire melting temperature consists of beveling the edges of the incoming end of the pipe, expanding the pipe, stripping and applying flux to those areas that form the joint.
The junction of cables in lead armor, due to the increase in the volume of the soldered cores, has a larger diameter than the cable itself. Therefore, lead couplings must be used.
It is quite common that you should always use quality products. The use of good lead free wire will help you in making orders in bulk.