Abstract: A joint construction is provided for lined equipment in which mutually weldable backing plates or sheets are lined with layer or facing sheets weldable to each other but not to the backing. An intermediate metal is optionally included between the backing and layer. A channel is provided between the layer sheets overlying the joint between the backings. A bridging strip weldable to the layer sheets is disposed in the channel and welded to the respective edges of the layer sheets. In some embodiments spaced strips of the layer material are disposed under the respective edges and the bridging strip and welds are made to join the spaced strips, the bridging strip and the edges of the layer sheets.

Abstract: A process for increasing the resistance to wear of the surface of hard metal parts subject to wear, such as a cutting blade of metal cutting tools, and the product which results from the process, which includes coating the surface of the hard metal, for example, cemented carbide articles with a first layer comprised of one or more layers of a metallic carbide or nitride in a total thickness ranging from 0.01 to 10 .mu.m, a second layer comprised of one or more layers of a refractory oxide, such as an oxide of aluminum, zirconium, silicon, calcium, magnesium, titanium, and hafnium, and stabilized zirconium oxide in a total thickness ranging from 0.5 to 10 .mu.m, and depositing over the refractory oxide coating a third layer comprised of one or more layers of a nitride, carbonitride, oxynitride, oxycarbide or oxycarbonitride and boride of such metals as titanium, zirconium, hafnium, aluminum and silicon in a total thickness ranging from 1 to 10 .mu.m.

Abstract: A process for recovering metal carbide powders from cemented carbides containing a metal binder phase by anodic dissolution of the binder phase under controlled electrochemical potential and current density conditions to produce a greatly accelerated rate of dissolution of the binder phase without significant dissolution of the metal carbide grains.

Abstract: A method of repairing a wall of chemical process equipment is disclosed which is particularly suitable for repairing a vessel having an outer shell and an inner liner having tantalum as a base constituent wherein the liner has a fault such as a corrosion pit. The fault is repaired by drilling a hole through the fault, liner and shell, the diameter of the hole through the liner being at least as great as the diameter of the fault. A lifting means such as a screw is inserted into the hole to raise the liner away from the shell. The hole through the shell is enlarged, the screw is removed from the liner, and the area between the raised portion of the liner and the shell is cleaned. An insert having tantalum as a base constituent is inserted into the hole, the areas on both sides of the insert are evacuated and purged with an inert gas, and the insert is welded to the liner to form a seal therebetween.

Abstract: A process for increasing the resistance to wear of the surface of hard metal parts subject to wear, such as a cutting blade of metal cutting tools, and the product which results from the process, which includes coating the surface of the hard metal, for example, cemented carbide articles with a first layer comprised of one or more layers of a metallic carbide or nitride in a total thickness ranging from 0.01 to 10 .mu.m, a second layer comprised of one or more layers of a refractory oxide, such as an oxide of aluminum, zirconium, silicon, calcium, magnesium, titanium, and hafnium, and stabilized zirconium oxide in a total thickness ranging from 0.5 to 10 .mu.m, and depositing over the refractory oxide coating a third layer comprised of one or more layers of a nitride, carbonitride, oxynitride, oxycarbide or oxycarbonitride .[.and boride.]. of such metals as titanium, zirconium, hafnium, aluminum and silicon in a total thickness ranging from 1 to 10 .mu.m.