What Are Malleable Iron Pipe Fittings?

Malleable cast iron, abbreviated as malleable iron, is the main material of our pipe fittings. Malleable iron pipe fittings hold two different pipe parts together and direct the gas and liquid movement. Some malleable pipe fittings are threaded, meaning that they have grooved ends that allow plumbers to screw the pipe fittings on the pipes, letting plumbers connect different pipes together.

It is an alloy composed of iron and C (carbon), Si (silicon), Mn (manganese), P (phosphorus), S (sulfur) and a small amount of other elements. In addition to Fe (iron), the content of C (carbon) plays a major role in the mechanical properties of steel, so they are collectively referred to as iron-carbon alloys. It is the most important and most used metal material in engineering technology.

¨Malleable cast iron, abbreviated as malleable iron, is the main material of our pipe fittings.¨

Malleable cast iron is high strength and toughness cast iron made of white cast iron after heat treatment. Malleable cast iron is cast iron made by pouring molten iron with a certain chemical composition into white blanks and then annealing. With high strength, plasticity and impact toughness, it can partially replace carbon steel.

From 1720 to 1722 AD, the French Réaumur invented the production method of whiteheart malleable cast iron later commonly known as the "European method" (Procédé européen). In 1982, American Seth Boyden decomposed Fe3C in white cast iron through accidental heat treatment, so that it precipitated flocculent graphite + metal matrix (ferrite or pearlite). The blackheart malleable cast iron he obtained at that time had a ferrite matrix. This method is often referred to as the "American Method."

● Whiteheart malleable cast iron: The outer layer is ferrite, and the center has a small amount of pearlite and flocculent graphite. Its heart port is white, so it is called white heart malleable cast iron. Since its outer layer is made of ferrite, its weldability is good. Due to the complexity of the process, there are few applications currently. Limited to thin-walled castings and castings that do not require heat treatment after welding.

● Blackheart malleable cast iron: developed from the white-hearted malleable cast iron process, the matrix is ferrite + flocculent graphite structure. At present, 90% of domestically produced malleable cast iron is black-hearted malleable cast iron. Because its carbon exists as flocculent graphite, it has good strength, high plasticity and toughness. Now our Jianzhi Group uses blackheart malleable cast iron as the material.

● Pearlitic malleable cast iron: malleable cast iron with a matrix of pearlite + flocculent graphite structure. It has high strength and hardness, and has poor plasticity and toughness compared to black core malleable cast iron. Manufacture castings with higher strength requirements and better wear resistance, such as gearboxes, camshafts, crankshafts, connecting rods, piston rings, etc.

¨Now our Jianzhi Group uses blackheart malleable cast iron as the material.¨

Although countries in the world have different standard names, in addition to the American standard, the standards of each country have similarities.

The tensile strength of our products exceeds 10% of EN 10242 (363 psi, exceeds class 150) and elongation after fracture exceeds 33% of European standard. We also have the certifications of ABNT, TSE, CE, UL and FM.