Quench tests

Steels having adequate hardenabiHty develop martensitic stmctures in practical section sizes. Molybdenum is a potent contributor to hardenabiHty, and has been shown to be even more effective in the presence of carehiUy selected amounts of other alloying elements (26). The end-quench test has become the accepted method for measuring hardenabiHty, and the data can be correlated with section size. Technical societies worldwide have standardized hardenabiHty limits (bands) for a large number of carbon and alloy steels standards of the Society of Automotive Engineers are examples (27). 

Hardenability is so important that a simple test is essential to measure it. The Jominy end-quench test, though inelegant from a scientific standpoint, fills this need. A bar 100 mm long and 25.4 mm in diameter is heated and held in the austenite field. When all the alloying elements have gone into solution, a jet of water is sprayed onto one end of the bar (Fig. 12.3). The surface cools very rapidly, but sections of the bar behind... 

Endo type aerators, types of, 26 164 End-quench test, 17 15-16 Enduron, molecular formula and structure, 5 162t... 

Quench tests, when the material is subjected to a sudden temperature decrease (A T< 0)... 

Becher, P.F., Warwick, W.H. (1993), Factors influencing the thermal shock behavior of ceramics , in Schneider, G.A. and Petzow, G. (editors), Thermal Shock and Thermal Fatigue Behavior of Advanced Ceramics, Dordrecht Kluwer Academic 37-48 Becher, P.F., Lewis, D.III., Carman, K.R., Gonzalez, A.C. (1980), Thermal shock resistance of ceramics size and geometry effects in quench tests , Am. Ceram. Soc. Bull., 59(5), 542-545... 

In this operation, dried propellant is discharged from dryers into a feed hopper. The propellant is fed at a uniform rate from the hopper to a vibratory feed conveyor and then to a vibratory collection conveyor. The collection conveyor moves the propellant through a fire wall and to the next operation. Flame quench tests were conducted by igniting a uniform one-inch deep layer... 

Infrared detectors were also used to detect the presence of flame at various conveyor locations including the end of the conveyor. High-speed color movies (200 frames per second) monitored each test to verify that flame propagation did, or did not, occur at the end of the conveyor. Rupture vents, determined to have little effect upon test results in preliminary trials, were blanked off using steel plates for some of the quench tests. 

Immediately after quenching, test pieces were maintained at each of these temperatures for 1, 2, 3, 4, 5, and 6 hours respectively, i.e. some at —20°, others at 0°, other at +20°, etc. 

Free radical scavengers - carbonate was selected in order to determine the effect of the free radical scavenger. Therefore, 0.5 M of sodium carbonate (NaoCOj) was added to the reaction mixture for quenching test. 

To verify the involvement of free radical reactions in dye ozonation at a high pH, a quenching test was conducted by the use of carbonate as the free radical scavenger (Hoigen J. and Bader H., 1976). The results of the quenching effect is shown in Figure 16,... 

The quench test was performed on two of the sintered bars, as representative samples, designated as Samplel Sample3 , (10 0.13 mm X 10 0.13 mm in cross section). The notation Samplel Sample3 corresponds to two bars having a difference in geometry, primarily thickness ail other processing parameters being exactly the same for both. The thickness was varied in order to study the influence of sample size on the response to thermal shock treatment. 

The mechanical as well as the high temperature properties of this material, have been studied in some detail. Bars fabricated using the slip-casting technique have shown good density. Young s modulus values and flexural strength, which corroborate the values reported in literature. Cyclic thermal shock quench tests have been performed on the bars, to study the effect on mechanical properties. These observations have been supported by microstructural analysis. 

P. F. Beoher, D, Lewis, K. R. Carman and A. c. Gonzalez, Thermal Shock Resistance of Ceramics Size and Geometry Effects in Quench Tests," Am. Ceram. Soc. Bull., [5] 542-48 (1980). 

Prism Test (Air Quench) (PRE/R5 Part 2), test pieces 114 x 64 x 64 mm are cycled between 950°C and a cold air blast for 5 min. followed by a bend test under a load of 0-3MN/m2. The cycle is repeated to rupture, or for 30 cycles. Small Prism Test (B.S. 1902 S.5.11 1986 Method 1902-511. The test pieces are 75 X 50 X 50 mm and subjected to 10 min. cycles between cold and 1000-1200 C, and subjected to an equal stress in each cycle. Testing is to rupture. Water-Quench Test (for unshaped refractories) B.S. 1902 Pt.7.6. The test is a water quench cycle from 1200 C to... 

U—ZrHi 6 has chemical compatibility with water. Zirconium hydride has low reactivity rates when exposed to water, steam, or air up to temperatures around 600°C. The corrosion rate of the fuel is very low. The results of water quench tests, for the purpose of investing the corrosion resistance and thermal shock resistance of the fuel, have shown no damaging effects on the fuel heated to 800°C. A surface discoloration was observed when fuel samples, which were heated up to 900°C, were quenched in water. Further experiments with fuel rods heated up to 1200°C showed cracks on the fuel pellets after being quenched in water. Nevertheless, no safety concern was caused, and the pellets were in good condition (Simnad, 1980). 

Hardenability, not to be confused with hardness, is the ability of a material to be hardened by a heat treatment. In steels, it is a measure of the ability to form martensite and is measured by the Jominy end-quench test. A Jominy bar is fashioned to AISI specifications... 

Determination of hardenability is accomplished by the standard Jominy end-quench test (Figure 11.12), from which hardenability curves are generated. 

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