Hardening rate of Resin-coated Ceramic Sand
(1) Swy hydraulic strength testing machine is installed. (2) The test method is to prepare two groups of patterns, and the second group of patterns is kept warm for 1min. The bending strength at room temperature of the two groups were tested respectively.
High temperature expansion rate of Resin-coated Ceramic Sand
(1) Definition
At the temperature of 1000 ℃, the percentage (%) of the linear shrinkage of the coated sand sample after white expansion to the original size of the sample.
(2) Device
Film coated sand prototype, the main machine is made of D 12 × 20 mm sample mould, heating, temperature control and time setting device, etc; High temperature strength tester for coated sand.
(3) Sample preparation
Heat the upper and lower heating plates of the prototype to 232℃, then remove the upper heating plate, put it into the normal temperature mold, quickly pour the coated sand into the mold cavity, use the blade edge of the scraper to be perpendicular to the mold, scrape off the excess sand on the mold, then press the upper heating plate, start timing, keep the temperature for 6 minutes, take out the sample, the sample is required to be compact as a whole, the two ends are flat and parallel, put it into the dryer for natural cooling, and the test is completed within 30 minutes.
(4) Test method
Lower the heating furnace of the high temperature strength tester for coated sand to a proper position so that the position of the sample to be tested is in the middle of the furnace, and raise the temperature of the heating furnace to the set temperature of 1000 ℃.
Put the sample in the middle of the furnace sleeve and record the maximum deformation displayed by the deformation sensor after the sample is heated and expanded freely.
(5) Calculation
Determine 5 samples, remove the maximum and minimum values, and take the average of the remaining 3 values as the final result. If any of the three values is more than 10% different from the average value, the test needs to be repeated.
High temperature heat resistance time of Resin-coated Ceramic Sand
(1) Definition
The non collapsing time of coated sand sample under constant load at 1000 ℃ is expressed in t (s).
(2) Test method
Lower the heating furnace of the high temperature strength tester for coated sand to a proper position so that the position of the sample to be tested is in the middle of the furnace, and raise the temperature of the heating furnace to the set temperature of 1000 ℃.
Put the sample in the middle of the furnace, apply a constant load of 0.2 MPa, and start recording the duration until the sample collapses, which is the high temperature heat resistance time under constant load.
High temperature compressive time of Resin-coated Ceramic Sand
(1) Definition
Pressure per unit area of coated sand sample at 1000 ℃.
(2) Test method
Raise the temperature of the heating furnace of the high temperature strength tester for coated sand to 1000 ℃. Put the clamped and adjusted sample into the furnace sleeve and start the heat preservation timing. After 1 min, the force measuring mechanism of the instrument will load the sample at the rate of 1 MMS and record the maximum load during the measurement process.