What is the process sequence of making concave die?
General to make die use of materials, processing capacity is larger, metal raw material waste, to machining and parts heat treatment is also difficult, for this application more 45 mn carbon structural steel and 40 or 45 or cr, 38 crmoala eight alloy steel.As shown in FIG. 2-21(a), the process order of making concave die with 45 steel is as follows.
1.forging die blank, leave 100 ^ 1 machining allowance according to the size of the drawing.
2.The billets are processed by direct heat treatment.
3.Press and draw the contour line of the concave die.
4.In the form of planer concave die, leave a finishing allowance of 2-3mm.
5.Flows the rough car concave die part, leaving a balance of 2 -- 3mm.
6.Receive heat treatment, conditioning 235 ~ 275H3.
7.The tool maker marks the contour line according to the drawing size.
8.Radial and concave dies of each side to size.
9.The rest 0.25-0.35mm is left in the concave die part of the shuttle precision car.
10.The tongs in each part of the mould are drawn by the tongs.
11.heat treatment, concave model cavity parts surface hardness 50 to 55 HRC.
12. fitter grinding cavity surface concave model, pneumatic grinding wheel grinding are available, and then use oil stone grinding, reoccupy metallographic sandpaper grinding.The granularity of sandpaper should be first thick and then fine.The grinding should be carried out in a direction perpendicular to the direction of the mark in the previous process, until the knife mark is removed, and then the grinding should be carried out in a direction perpendicular to the direction of the first grinding.During the last grinding, the direction of grinding should be consistent with the direction of product demoulding, so as to facilitate the smooth demoulding.After grinding, the roughness Ra of cavity surface should not be greater than 0.25um.
13.Each part of the bench drill tapping silk hole.
14.Each part of the pare off burrs.