Study On Laser Heat Treatment Of Cylinder Block Of The Introductive Pump

The pump of B array is a filled pillar pump produced by our country with introductive technology, its key part cylinder block doesn't wear resistant in national.QT600-3 Nodular iron, a more ideal substitution of cylinder block, is founded by years' effort, but it deforms greatly in the normal quenching. Laser quenching takes the advantage of having a fast cool speed and a short fix time which can solve the wear resistant less and deformation problems.With the development of high power laser, much progress has been made in laser quenching processing and parameters optimization included which introduces the QT600-3 material and strengthen principles, facilities as well as the specific steps of experimentThe surface-quenching of QT600-3 material was carried out with a laser rectangle beam. The surface-hardness distribution and hardened depth with the hardened layer were studied. When he light spot is 5mm X 4mm, with the best laser power between 4 and 5.5 kw/cm2,the scanning speed at 4-5.5mm/s,the hardened with 4mm,the average misro-hardeness of Qt600-3 can reach 950Hv, Which is about 2.3 times as high as that of normal hardness, also the depth of 0.55mm is obtained. The hardened layer consists of two sub-layers, uniform phasetransfomation laser and transition layers. The material after laser quenched is obvious much more wear resistant than normal one.The study of QT600-3 cylinder block with wide-hand laser quenching which bused on the laser quenching optimal parameters of QT600-3 indicates that the hot process used by the QT600-3 cylinder block are: laser quenching wide-band CO2 laser scanning with the processing parameters are 4-5kw/cm2 of power and 4-5.5mm/s at speed. Then the wear resistance and little deformation of cylinder block can realize, so the key technique of B array pump can be solved completely.