Things to note when selecting high-temperature mechanical equipment for metal materials

2017-06-01

1. Standards related to high temperature mechanics of metal materials:

GB/T4338 "High Temperature Tensile Test Methods for Metallic Materials",

HB5195 "Metal High Temperature Tensile Test Method"

GB/T2039 "Metal Tensile Creep and Durability Test Methods",

HB5150 "Metal High Temperature Tensile Durability Test Method"

2. Test content and electric furnace structure

High-temperature mechanical tests of metal materials are mostly high-temperature tensile and creep endurance tests. When conducting such tests, you can choose a barrel-type atmospheric furnace. In addition to being used for tensile and creep tests, the GWT-1200 atmospheric furnace can also be used for tensile and creep tests. Compression, bending and shear specimens of small specimens. The standard high-temperature furnace inner diameters are 90mm and 110mm. As long as the diagonal length of the fixture and deformation measuring device is smaller than the inner diameter of the furnace tube, this type of high-temperature furnace can be used. The high-temperature furnace structure adopts a split type to facilitate test operations.

If you need to carry out three-point bending, four-point bending of large-size samples and tests where the above two specifications of furnace tubes cannot meet the requirements, you need to configure a box-type electric furnace. The volume and weight of the box-type electric furnace are larger than that of the barrel-type furnace. The open-door structure requires a large space for the testing machine. When configuring this type of high-temperature furnace on the original testing machine, it is necessary to confirm that the span of the testing machine is larger than the external dimensions of the high-temperature box.

3. Temperature range:

When selecting equipment, you should first clarify the actual operating temperature. The operating temperature is mostly between 100 and 1200°C. The furnace structure, heating element type, insulation layer thickness, and insulation material type can be determined according to the operating temperature. Among them, 350°C and 500°C are the critical points. Considering the thermal deformation factor of the inner cavity material, stainless steel inner cavity is selected below 350°C, heat-resistant steel material inner cavity is selected between 350°C and 500°C, and ceramic material inner cavity is selected above 500°C.

4. High temperature fixture

High-temperature fixtures account for a large proportion of the purchase cost of the entire set of equipment, and the most important factor related to it is the operating temperature. Among them, 500°C, 600°C, 950°C, and 1050°C are critical temperatures. Different high-temperature alloy materials are selected to make clamps for different operating temperatures.

5. Deformation measurement

There are two methods to choose from for high-temperature tensile test deformation measurement: bilateral extraction method measurement and direct measurement with imported high-temperature extensometer.

Both methods can meet different test requirements. The cost of accessories required by the bilateral extraction method is slightly lower and the operation is more cumbersome. The imported extensometer is directly tied to the test gauge section, which is simple to operate, but requires a reserved jack on the high-temperature furnace.

6. Connection between high temperature furnace and testing machine

When purchasing the high-temperature tensile or long-lasting creep test system as a complete set, just install the high-temperature furnace directly on the column, and adjust the position by rotating the arm. If you use a box-type electric furnace or add a high-temperature device to the original testing machine, you need to configure a movable bracket with a track that can be flexibly moved in and out of the test area.