What are the common heat treatment processes of cast basalt slab?

Common heat treatment processes of cast basalt slab include normalizing, annealing, solid solution, aging, quenching, tempering, annealing, carburizing, nitriding, quenching and tempering, spheroidizing, brazing, etc

1. Normalizing: the heat treatment process of heating steel or steel parts to an appropriate temperature above the critical point AC3 or ACM for a certain time and cooling in the air to obtain pearlite structure.

2. Annealing: the heat treatment process of heating hypoeutectoid steel workpiece to 20-40 degrees above AC3, holding for a period of time, slowly cooling with the furnace (or buried in sand or lime) to less than 500 degrees and cooling in air.

3. Solid solution heat treatment: heat the alloy to the high temperature single-phase zone, maintain the constant temperature, fully dissolve the excess phase into the solid solution, and then cool quickly to obtain the heat treatment process of supersaturated solid solution.

4. Aging: the phenomenon that the properties of an alloy change with time when it is placed at or slightly higher than room temperature after solution heat treatment or cold plastic deformation.

5. Solution treatment: fully dissolve various phases in the alloy, strengthen the solid solution, improve toughness and corrosion resistance, eliminate stress and softening, so as to continue processing and forming.

6. Aging treatment: heat and keep warm at the temperature of strengthening phase precipitation, so that the strengthening phase precipitates, hardens and improves the strength.

7. Quenching: a heat treatment process in which the steel is austenitized and cooled at an appropriate cooling rate to make the workpiece undergo martensite and other unstable structural transformation in the cross section or within a certain range.

8. Tempering: it is a heat treatment process that heats the quenched workpiece of cast basalt slab to an appropriate temperature below the critical point AC1 for a certain time, and then cools it with a satisfactory method to obtain the required microstructure and properties.

9. Carbonitriding of steel: carbonitriding is the process of infiltrating carbon and nitrogen into the surface of steel at the same time. Traditionally, carbonitriding is also called cyaniding. Cast basalt plate is widely used in medium temperature gas carbonitriding and low temperature gas carbonitriding (i.e. gas soft nitriding). The main purpose of medium temperature gas carbonitriding is to improve the hardness, wear resistance and fatigue strength of steel. Low temperature gas carbonitriding is mainly nitriding, and its main purpose is to improve the wear resistance and bite resistance of steel.

10. Quenching and tempering treatment: Generally speaking, the heat treatment combining quenching and high temperature tempering is called quenching and tempering treatment. Quenching and tempering treatment is widely used in various important structural parts, especially those connecting rods, bolts, gears and shafts working under alternating load. Tempered sorbite was obtained after quenching and tempering, and its mechanical properties were better than normalized sorbite with the same hardness. Its hardness depends on the high temperature tempering temperature and is related to the tempering stability of steel and the cross-section size of workpiece, generally between hb200-350.

11. Brazing: a heat treatment process in which two kinds of workpieces are heated, melted and bonded together with solder.