Cooling surface quality

During hot rolling, the most important function of the lubricant is cooling but it should also reduce energy consumption, provide good surface quality of the rolling stock and achieve maximum thickness reduction of the rolled material. Thus, friction is also important. 

The characteristics of individual forms of corrosion are taken into consideration by providing appropriate corrosion specimens. Welded coupons having the surface quality of the material used later in practice are sufficient for determining uniform corrosion rates and acquiring general information on the type of local corrosion. Resistance to crevice corrosion can be determined by using specimens as described in ASTM G 78-83. Conditions of heat transfer can be simulated by using hot-wall/cool-wall specimens under temperature-controlled conditions. 

Another method of adjusting cooling channels to a complex mold is selective laser sintering, which makes it possible to build almost all metallic materials in layers. Single-component metal powder is layer by layer completely melted. A component density of nearly 100% is thereby achieved. High surface quality and hardness is achieved through a special surface treatment process that directly follows the construction process. 

Because small polymer particles are produced, fouling of the reactor surface must be minimized. When the fouling occurs, the heat transfer coefficient for the cooling surfaces decreases and the reactor temperature control becomes difficult. Furthermore, the deposits are peeled off from the inner surface of the reactor and mixed into the polymer. As a result, the quality... 

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