Aluminium Window Door Hardware Square Tube Corner Connector

Quenching crack

If the steel is overheated, the austenite grows up. The thick-needle martensite produced during quenching will collide with each other, causing stress concentration and transverse cracks. During quenching, the surface of the part is subjected to tensile stress and the center is subjected to compressive stress; at this time, one situation is that the crack is on the surface of the part, which is generally deeper and thicker. However, the grain size of this product has reached the ISO standard 8 level, which is obviously not overheating. When the shape of the part is more complicated, cracks are also prone to occur at corners, grooves or sharp corners. However, in this case, a large number of magnetic marks appear on the flat surface of the workpiece, which at least shows that there are internal factors other than the shape.

Please contact us at zhang@pride-cnc.com