I deal with
aluminum plate material 2A12, thickness 14mm, crack, same temperature treatment, diameter 8mm aluminum bars, no cracks, original
aluminum plate quenching crack, and
aluminum plate, the material is closedThere are no special cracks in the aluminum bars, such as 1 of the heat distortion, 3 of the metallurgical quality, 2 of the solid solution system, the reasonable analysis of the crack location and appearance1. Crack type: longitudinal crackFeatures: by table and depthShape conditions: hardenability of the workpiece, easy to produce raw materials, carbide band segregation or non-metallic inclusions extensionPreventive measures: control raw material quality, select preheating treatment, improve original organization2. Crack type: net crackFeatures: located on the surface of the workpiece, depth 0.01 ~ 2mmSurface conditions: surface decarburization, heat treatment, surface hardening, easy to presentPrevent measures: take heating protection, avoid decarburization, delay quenching cooling, reduce quenching temperature3. Crack type: arc crackFeatures: located at the corner of the workpiece, hidden in the surface layerShape conditions: prone to Weicui through the workpiece or carburized partsPreventive measures: change workpiece design, cross section fillet rationalization4, crack type: peel crackCharacteristic: showing the delamination of hardened layerShape condition: surface hardening parts or heat treatment partsPrevention measures: reasonable choice of medium, delay cooling5. Crack type: microcrackFeatures: defects in microstructureShape conditions: hardening of high carbon martensite nearPreventive measures: avoid heating, hot, coarse grainIf the material is right may be burned, a full air bubble is parts of the surface, whether the intergranular cracking section, part to do see the metallographic analysis of grain size, lower furnace installed furnace capacity amount control too much away from the direction of the thermocouple parts temperature indicator indicates the temperature to the temperature time lag of thermocouple thermocouple has high temperature parts away from the direction. 510 is enough to regularly test the stove uniformity and precision with 2 kinds of stove fan checkOther related question