Chrome carbides

Charcoal Chrome Carbide Clay, Attapulgite Clay, Bentonite Starch Gel Alcohol Water Water Briquetter Disc Pelletizer TurbulatorVDisc Turbulator ... 

A control method variation uses the output signal from a temperature control in a downstream zone as process variable for energy input in the next upstream zone, for example, soak zone temperature controls main heating zone input and/or heat zone temperature controls preheat zone temperature. Note that zones may sometimes be a series of closely spaced, separate catenary furnaces. If a very low setpoint for the output signal of the soak and/or heat zones is used to control the upstream zone, the soak time will be extended to allow the chrome carbides to dissolve into the strip and thereby produce a quality product. 

Table 11.2. Creep rupture strength of several alloys (after [39,125,129]). The creep rupture strength iim/iooooo/T i- e., the stress needed to cause fracture in a specimen at temperature T after 10 hours (creep rupture time), is stated. The creep resistance of the ferritic steels with large amounts of vanadium and chromium is significantly larger than that of simpler steels because vanadium and chrome carbides have a better temperature stabihty. Due to their close-packed face-centred cubic structure, the creep resistance of austenitic steels is larger. The creep strength of the nickel-base superalloys IN 738 (polycrystaUine) and SC 16 (single crystalline) were estimated from Larson-Miller data...

From 760 to 960°C, circulating fans, normally without baffles, are used to improve temperature uniformity and overall heat transfer by adding some convection heat transfer. They create a directional movement of the air or atmosphere but not the positive flow past the heating elements to the work as in a convection furnace. Heating elements ate commonly chrome—nickel alloys in the forms described previously. Sheathed elements are limited to the very low end of the temperature range, whereas at the upper end silicon carbide resistors may be used. In this temperature range the selection of heating element materials, based on the combination of temperature and atmosphere, becomes critical (1). 

Chrome—nickel alloy heating elements that commonly ate used in low temperature furnaces are not suitable above the very low end of the range. Elements commonly used as resistors are either silicon carbide, carbon, or high temperature metals, eg, molybdenum and tungsten. The latter impose stringent limitations on the atmosphere that must be maintained around the heating elements to prevent rapid element failure (3), or the furnace should be designed to allow easy, periodic replacement. 

A hard, mst-resistant shaft of at least 0.25 micrometer finish is usually required. Common shaft surfaces are hardened tool steel, chrome plate, high strength bronze, and carbide and ceramic overlays. Test results over a broad speed range from 0.05 to 47 m/s (10 to 9200 fpm) iadicate that a coefficient of friction of 0.16—0.20 and a wear factor of 14 X 10 m /N(70x 10 ° in. min/ft-lb-h) are typical for dry operation of weU appHed grades of carbon—graphite (29). 

Chrom-kali, n. (rotes) potassium dichromate (gelbes) potassium chromate, -karbid, n. chromium carbide, -lack, m. chrome lake, -leder, n. chrome leather, -leim, m. chrome gelatin chrome glue, -metall, n. chromium metal, -natron, n. (rotss) sodium dichromate (gelbes) sodium chromate, -nickel-stahl, m. chrome-nickel steel. 

A. Tungsten carbide has replaced chrome plating on oil field piston rods over the last five years. 

The tungsten carbide has excellent wear characteristics and does not flake. Piston rods coated with tungsten carbide do not need recoating like chrome did except for external damage. The benefit to the user is longer operational life, thus, lengthening the period between overhauls. 

Chromium. Phis element increases hardness, improves hardenahilily. and promotes the formation of carbides and for tliese reasons is used in eonstt uelional steels Chrome steels are relatively stable at elevated temperatures and have outstanding wear resistance. Chromium is an important constituent of stainless and heat-resistant steels to be described shortly. 

Basic Raw Materials. Basic raw materials include magnesite dolomite, forsterite, chrome ore. silicon carbide, beryllia, thona. and carbon... 

Potassium Amide or Potassamide A169-R Potassium Azide A594-R Potassium Azidodithiocarbonate A634-L Potassium Carbide A79-L Potassium Chrome Alum. See under Alums A156-R... 

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