Of rail of Hong Kong subway solder method

Hong Kong railroad is used generally will solder the method of long course basically is thermit crimp law (Thermit Welding) and lightning correct solder law (Flash Butt Welding) . Thermit crimp law is to use tailor-made aluminium powder, mixture ferric oxide powdery Fe2O3, use displacement to react (the principle of Displacement Reaction) solders (namely the metal with a kind of lively taller sex metal of a kind of inferior and lively sex in the compound from it draw-out come out, more lively metal turns into compound) . And lightning correct solders the resistance that law uses rail will heat rail, your rail interface is dissolved make its joint. Of thermit crimp law solder program: 1.

Mix aluminium powder and ferric oxide pink contain 2.

Will ignite, achieve in heating power centigrade 1000 iron solution Fe(l) 3 can arise when spending.

Handle iron solution by the rail connect of preheat of arenaceous model infuse again, pursue as follows: 4.

After waiting for rail to dissolve will joint 5.

After rail is cooling eliminate of will arenaceous model, wear course face again smooth become, pursue as follows: Chemical type: 2Al(s) + Fe2O3(s)---->Attention of Al2O3(s) + 2Fe(l) : The alumina that produces after chemical reaction is met the surface on float so won't inside interfuse iron solution. The rail that place of thermit crimp law solders, although contact intensity amounts to the 85% of intensity of mother capable person only, but its advantage is equipment simple, can be in construction of building site TRANBBS, suit to be used at narrow little place. Note: Above pursues two pieces piece all cento serves acceptance from 9 wide light iron inside 1999 booklet. Lightning correct solders of the law solder program: 1.

the cleanness of rail joint surface that is about to solder clean 2.

Be opposite course of two bar iron neat, connect next on big electric current (need to use low tension) 3.

Touch course of two bar iron gently, the high fever that rail resistor place produces can make interface fuses 4.

After waiting for rail to cool, wear the face smooth solder into lightning correct of the law solder strength is great, amount to the 99% of mother capable person, but requires equipment is larger, need to be inside workshop so construction. The equipment that lightning correct solders arrives by workshop building site: Because the space of rail laid spot is general very few also, so welder foreword can undertake inside workshop as far as possible. Law of crimp of iron use thermit is in east the length that workshop solders the rail of every long 25m into 100m first, the rail link that carries spot of past building site uses same method and the rest again rises; and correct of subway criterion use lightning solders law at growing every in workshop the rail of 18m solders to grow into 72m, carry past building site uses thermit crimp next the join of law general grows course. CNC Milling