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I have to know a few key points of the Chinese square tube quenching in Shenzhen Building Materials Factory.

When the Chinese rectangular pipe of Shenzhen Building Materials Factory is quenched, the following points should be noted:

(1) The slender pipe should be hung vertically in the salt bath furnace or the pit furnace to reduce the deformation caused by its own weight.

(2) When the pipe fittings with different cross-sections are heated in the same furnace, the small pieces shall be placed at the outer end of the furnace, and the small and small parts shall be taken out first.

(3) The amount of furnace loading should be compatible with the power of the furnace. When the amount of furnace is large, the temperature is easy to be pressed, and the heating time needs to be extended.

(4) The workpiece with quenching water or salt water, the lower limit of quenching temperature, the workpiece of hardened or molten salt, the upper limit of quenching temperature.

(5) When double-material quenching, the time of residence in the first quenching medium is controlled by the above three methods, and the time from the first quenching medium to the second quenching medium should be as short as possible, preferably 0.5-2 s. .

(6) Pipes that are not allowed to oxidize or decarburize on the surface shall be heated in a calibrated salt bath furnace or a protective atmosphere furnace. If the conditions are not available, it can be heated in the air resistance furnace, but protective measures should be taken.

(7) After the square tube is vertically immersed in the quenching medium, it is not oscillated, only moves up and down, and stops the agitation of the quenching medium.

(8) When the cooling capacity of the pipe with high hardness requirements is insufficient, the whole part may be immersed in the quenching medium, and the part is further cooled by spray to increase the cooling rate.

(9) It must be placed in the effective heating zone. The furnace loading, furnace loading method and stacking mode should ensure that the heating temperature is uniform and does not cause distortion and other defects.

(10) When heating in a salt furnace, do not rely on the electrode too close to prevent local overheating, the distance should be above 30mm. The distance from the furnace wall and the depth below the immersion level should be 30 mm or more.

(11) When quenching hardening, the quenching temperature may be appropriately increased to increase the stability of the austenite of the rectangular tube and prevent it from decomposing into pearlite.

(12) Structural steel and carbon steel can be directly charged into the furnace at a quenching temperature or 20-30 ° C higher than the quenching temperature. The high-carbon high-alloy steel should be preheated at about 600 °C and then raised to the quenching temperature.

(13) For the pipe with deep hardened layer, the quenching temperature can be appropriately increased, and the quenching temperature is required to select a lower quenching temperature.

(14) There shall be no oil, soap or other dirt in the cooling water of the rectangular tube. Under normal circumstances, the water temperature does not exceed 40 ° C, the oil temperature does not exceed 80 ° C.

What are the key points of heat treatment of the Chinese rectangular tube in Shenzhen Building Materials Factory? Let's analyze it:

(1) The circuit device is normal

Always pay attention to check whether the automatic power-off device of the opening and closing furnace door is good, and whether the traffic lights on the power distribution cabinet work normally.

(2) Preventing gas leakage

When the rectangular tube is subjected to heat treatment, special attention should be paid to prevent poisoning caused by leakage of special gas.

(3) Taking cooling measures

During the heat treatment, some cooling measures should be taken to control the temperature of the quenching oil tank below 80 °C.

(4) Equipment inspection

When the square tube is subjected to heat treatment, the equipment must be inspected frequently. The oil pipe and the air pipe must not leak oil or leak, and there should be no heavy oil at the bottom of the furnace.

(5) Preventing short circuits from occurring

When operating the heat treatment, it should be noted that no other debris should be placed on the console to avoid short circuit.

(6) Pay attention to prevent electric shock

When the square tube is subjected to heat treatment, special care should be taken to prevent electric shock. The floor of the operating room should be covered with a rubber pad and care should be taken to prevent the cooling water from spilling on the floor and other places.

The above is the relevant content of the Chinese rectangular pipe of Shenzhen Building Materials Factory. I hope to help everyone. I would like to know about the galvanized angle groove and the galvanized flat iron. Welcome to Sheng Jinlong's official website. I look forward to your coming.