Showing papers on "Gray iron published in 1996"
TL;DR: In this paper, the results of cyclic furnace tests from room temperature to 1100 °C in air, simulating the thermal cycle in casting, indicated that failure occurred along the interface between the bond coat and the gray iron substrate because of iron oxidation.
Abstract: Molds made of gray cast iron for casting pig iron ingots are subjected to severe temperature fluctuations. The main life- limiting factor for mold damage is the formation of surface cracks arising from thermal fa-tigue. Various flame and plasma sprayed coatings were investigated to extend the life of these molds. Coating materials studied include plasma sprayed ceramic coatings with bond coats as well as flame sprayed oxidation- resistant alloy powders. The results of cyclic furnace tests from room temperature to 1100 °C in air, simulating the thermal cycle in casting, indicated that failure occurred along the interface between the bond coat and the gray iron substrate because of iron oxidation, and not at the interface between the ceramic top coat-ing and the bond coating for a superalloy substrate. The field test results indicated that plasma sprayed alumina coatings with 200 µm top coating thickness are the most promising materials for pig iron casting.
7 citations
TL;DR: In this article, the effect of small Te additions on the transition velocities between gray to white cast irons during acceleration and the reverse transition (white to gray) during deceleration was investigated.
Abstract: In a recent study, directional solidification experiments were employed with increasing and decreasing velocities to evaluate the effect of small Te additions on the transition velocities between gray to white cast irons during acceleration, V{sub g-w}, and the reverse transition (white to gray) during deceleration, V{sub w-g} The irons had a hypoeutectic composition of 34 wt pct C, 2 wt pct Si and were doped with 01 wt pct Te In an extension of this work to lower Si levels, a hypoeutectic iron of 39 wt pct C, 1 wt pct Si + 005 wt pct Te, an important discovery was made involving the effect of H on the transition velocities In conclusion, the authors have made the following discoveries: (1) small additions of H to the atmosphere present in directional solidification experiments of Te-doped cast irons have a large effect on the gray-white and white-gray transition velocities; (2) addition of 10% H to the atmosphere allows growth of white cast iron at rates down to 1 and 25 {micro}sm/s in irons containing 1 and 2 wt pct Si, respectively; (3) it appears that the action of the H is to reduce compounds of Te, most likely oxides, thereby allowingmore » more Te to remain in liquid solution and to adsorb on the graphite/liquid iron growth front interfaces; this, in turn, reduces the graphite growth kinetics and permits white iron growth to dominate« less
Patent•
26 Sep 1996
TL;DR: In this paper, a method for producing a brake component involves providing a cast gray iron rotatable brake component where the gray iron has a carbon content between 3.4 % and 4.0 %.
Abstract: A method for producing a brake component involves providing a cast gray iron rotatable brake component where the gray iron has a carbon content between 3.4 % and 4.0 %. The brake component is subjected to an austempering heat treatment process. Then it is subjected to a re-tempering process to provide a microstructure which consists of spheroidized pearlite carbon in a matrix of bainitic and austenitic ferrite.