Brochure: A Synopsis of Analytical Procedures - Timcal

Analytical proceduresfor TIMREX ® and ROLLIT ®DispersionsFriction measurementwith Tribo-MeterThe friction is measured between twosteel specimens chosen to represent thepierced shell (the upper specimen) and themandrel (the lower specimen) during therolling of seamless tubes. The test is automatedand consists of several steps. The firststep consists of coating the lower specimenwith the lubricant. The upper specimen isheated in-situ to 1050 °C and positioned automaticallyover the lubricated piece that holds atemperature of 100 °C.The upper specimen (the shell) is thereafterreleased and a load is applied hydraulicallywhile the lower specimen (the mandrel)is being pushed forward with a motor.The friction force is measured during thedisplacement. A computer calculates the frictioncoefficient and energy dissipated duringthe sliding. The test variables are the slidingspeed, the load and the temperatures.Reference:- TIMCAL methodSolid contentnThe solid content is measured using aHalogen Moisture Determination thermobalance.nIn this procedure 1 to 2 g of the dispersionare placed on the sample holder and driedat 120 °C until a constant weight isachieved.nThe remaining weight is recorded andexpressed as a percentage.Reference:- TIMCAL methodViscosity and flow behaviourViscosity is measured in the steady state asa function of the shear rate as well as in oscillatingmode as a function of the amplitudewith a constant frequency. Thixotropicbehaviour is measured by observing the viscosityin an oscillating test as a function of thetime. A rotational rheometer with a coneplatesetup is used and the measurements areperformed at room temperature.1-2 grams of liquid sample are put in thegap between a stationary plane and a rotatingcone. A laminar flow of layers is created. Theviscosity is obtained from measuring theinternal resistance and a flow curve isobtained.Reference:- TIMCAL methodWetting testIn the wetting test the quantity ofremaining graphite on steel surfaces ismeasured after being sprayed with dispersions.The test has been developed to simulatethe behaviour of the dispersion whensprayed as a lubricant on a hot mandrel inthe seamless tube production.Steel plates are being weighed and heatedto the desired temperature in an oven andthereafter put on a sliding support. The dispersionis sprayed with a typical pressure of50 bar on the steel plates passing under thespraying unit with a speed of 1.5 m/s. Thesteel plates are dried and weighed to obtainthe deposited graphite quantity as well as itsthickness.Reference:- TIMCAL methodpHThe pH is measured using a Digital pHMeter with a calibrated pH electrode.The clean electrode is immersed into theliquid. After stabilization of the reading thepH is recorded.Reference:- TIMCAL method