What can you do and not do the welding of cast iron? If cast iron welding without heating to above 480 ° C (900 ° F), soldering, and acetylene / oxygen welding at 650 ° C (1200 ° F), and in all types of electric welding, and caused two kinds of serious problems: 1. Tensions and new cracks caused by expansion and contraction. 2. Curing of iron on the edge of the weld. Tensions and new cracks occur if you try to weld cast iron without preheat to a sufficiently high temperature so that the weld is surrounded by colder iron that keeps hair locked. Cast iron has yield consistent with its tensile strength which makes cast iron can not stretch to equalize tension in the material, like most other metals can. Any material that can bend without cracking can be welded without preheating at high temperature. Normalization of the stresses in cast iron occurs at temperatures between 980 ° C (1800 ° F) and 650 ° C (1200 ° F), if the material is cooled down slowly. When the material is preheated to high temperatures creates a temporary artificial yield that is lower a material's tensile strength. This means that the surrounding material can expand when the weld cools and contracts, allowing the formation of stresses and cracks. In the same way as steel can be bent when it warms up, then cast stretch rather than crack at the proper temperature. Curing takes place by weld or zone around affected by heat (Heat affected Zone, Haz), cool down too quickly. Rapid cooling of iron with high carbon content and steel will cause hardening. The cast iron will cause hardening material is brittle and lose the good qualities as vibration damping and formability (deformation before failure). Hardening of cast iron will also make it difficult if not impossible to machined, drilling and thread in the material. The conclusion is; "If the formation of cracks around a weld, it was not preheated properly. If cast iron was hard, so it was cooled too quickly. " Corners and "ears" sticking out, welded without the risk of tensions and cracks occur because the material can expand and contract without stresses occur. However, if the material is cooled too fast it will be hard. It does not matter which wire welding or the welding method used. It is the temperature that causes cracks and hardness. Martinius.
Cast iron Weldments I'm no welder but I've watched it being done and it is nearly a Black Art . And a lost one at that . The entire piece should be pre - heated but that's not always possible. Back in my day , Cast iron Welders had a bix box of ashes and this was used to slowly cool the heated part after it was heated up and welded . I know this is just a bit of useless info but it is all I have for you , sorry .
I've done a little bit of cast iron welding and had good luck, What I do is clean the piece that I'm going to weld first, then groove out any cracks or leave a gap if I'm welding two pieces together, then preheat the entire piece to be welded first. I just set the torch to acetiline only and smoke the whole area that I'm going to preheat then I set the torch to a neutral flame and start heating. When the black smoke is burned off then the part is hot enough to weld. I've used nickle rod and it works OK but I prefer brass cause it's easier to work with. After the welding is done just wrap the piece up in some insulation or a welding blanket or anything that will a lough the part to cool slow. I've done this with cast aluminum and cast iron and have had good luck...Big Tim
Cast iron welding and dids and thats. Hey Nate Dayly comen knowledge about cast iron welding is lost fore many persons because much is moved to other countrys whom still have these knowledges like China and Poland.I myself have heated the part up with gas acyteline and used brass rods basicly , cooled the parts down in fine silversand or blasting sand. This works just fine. Some people also weld cast iron cold with spesial cast iron electrodes, but that is not allways with good results.Depends of the qualety of the cast iron object to weld offcourse. In the older days and still Norway did had quite a big steel/Iron industry between in the epoke between (1750-1970) because of there big nature iron resources. Cast iron heating ovns procuction, and other product made of iron are still in use in many homes and produced. The factory Jøtul is the biggest here now. Pictures still show how beautifull the Jugend style and Emperic style ovns where made. As it concerns car industrial devellopment during the years Norway has never been a big country.But they still make a lot of parts in steel and alum. fore the BMW and Mercedes factory in Germany. Norway produced and patented there first electrical car allready in 1904 i think it whas made by Madshus. Another car by the name off Troll in duroplastic/fiberglass had a 2 tact engine and 3 cyl. http://home.online.no/~bjarnli/troll/Tekniske_Data/tekniske_data.html Today the el.driven car with the name Think produced in Norway is an populair product fore city people. GM sold all there stocks to a Norwegian/Swiss compagny last year after the total finance colaps al over the world. http://www.think.no/ Friendly regards Martinius.
I hear of some that fire up the grille after welding, put the part in, then turn off the flame, keeping the lid closed until completely cooled. Also burying in sand.
