ISO 8493:1998 pdf download – Metallic materials –Tube —Drift-expanding test.
ISO 8493 specifies a method for determining the ability of metallic tubes of circular cross-sectionto undergo plastic deformation in drift expansion.
This Intermnational Standard is intended for tubes having an outside diameter no greater than 150 mm (100 mm forlight metals) and a thickness no greater than 10 mm although the range of the outside diameter or the thickness forwhich this International Standard is applicable may be more exactly specilied in the relevant product standard.
2 Symbols, designations and units
Symbols, designations and units for the drift-expanding test of tubes are given in table 1 and are shown in figure 1.
3 Principle
Expansion of the end of the test piece cut from the tube, by means of a conical mandrel, until the maximum outside
diameter 04th. expanded tube reaches the value specified in the relevant product standard (see figure l)
4 Testing equipment
4.1 Variable-speed press or universal testing machine
42 ConIcal mandrel, which thai have an angle as specified in the relevant product standard and Its surface thai be made of polished material of sufficient har&iess.
Preferred angles for the conical mandrel are 30, 45 and 6&.
5 Teat pIece
5.1 The length of the lest piec. depends on the angle of the cone of the drift-expansion conical mandrel When this angle is equal to or less than 30, the length ci’ the test piece shall be approximately L = 20. When thés angle Is greater than 30, the length of the lest piece shall be approximately L 1,50.
The teal piece may be shorter provided that the remaining cylindrical part of the test piece after expansion is at least
52 Both ends of the test piece shall be Ni the plane perpendicular to the axis of the tube. The edges of the end to be tasted may be rounded by filing or chamfered by other methods.
NOTE — Non-round.d Or ncn-chwilarad edge. are pemissibl. if the test rwit meets the lest r.quvements. $3 When welded tubes are subjected to the test, th internal weld flash may be removed.
6 Procedure
6.1 In general, the test ahai be carried out at ambient tenperature within th. limits of 10 C to 35 C. The test carried out under controlled Conditions shall be made at a terrperatur of 23 C * 5 C.
62 Force the conical mandrel into the teat piece, without shock, until the required outside diameter I. reached. The axis of the conical mandrel shall be aligned with the axis of the tube.
The maximum outside diameter 04 the expanded part of the teal piece. D, or relative expansion as a percentage of the odginal diameter, 0, shal be specified Wi the relevant product standard. The angle of the Conical mandrel. , may be specified in the relevant product standard.
When longitudinally welded tub., are subjected to the test, the conical mandrel may be provided with a groove to socommodat. an Internal weld flash.
6.3 The conical mandrel may be lubilcated. It shall not rotate relative to th. test piece during the test.
6.4 In case of dispute, the rate of penetration of th. conical mandrel shall not exceed 50 rrwrVmln.
6.5 Interpretation of the drift-expanding test shall be carried out in accordance with the requWemenls of the relevant product standard. When these requWernents ai- not specified, the test piece shall be considered to have passed the test ii no cracks are visible without the use of magnifying aids. Shght cracking at the edges shall not be considered cause for reacjion.