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brass tube and stainless steel fitting solution

author:MF manufacturerstime:2022-03-15 01:19:05

The welding situation of copper and stainless steel is often encountered,Welding is difficult,Mainly as:It is very sensitive to copper penetration cracks during welding,To prevent penetration cracks,First of all, we must choose a reasonable process,Choose a small welding line energy;The second is to choose the appropriate filling material,Control elements that are prone to low-melting eutectics,Such as:S、P、OWait,add to weldAl、Si、Mn、V、Mo、Nietc. elements。

(brass tube and stainless steel fitting solution)

two,Welding method

Manual arc welding

When using manual arc welding of copper and stainless steel,Note that if you choose austenitic stainless steel electrodes, it is easy to cause hot cracks;The best choice for nickel-Copper electrode(70%nickel+30%copper),or nickel-based alloy electrodes,Also available with copper electrodes(T237);Welding process with small diameter, small current and fast welding without swinging during welding,and biases the arc to the copper side,to avoid penetration cracks,Welding process parameters are shown in Fig.1。

brass tube and stainless steel fitting solution

Submerged arc welding

The main problem when using submerged arc welding of copper and stainless steel is cracks and pores;Strictly clean the surface of the weldment and welding wire before welding,8~10mmthick weldment,Normally open70°Vbevel,The breaking angle of the pure copper side is40°,Stainless steel(1Cr18Ni9Ti)The bevel angle on one side is30°,Flux usedHJ431orHJ430(200℃bake2h),Welding wire is generally made of copper wire,and placed in the groove1~3Nickel wire or nickel-copper alloy wire;Choose a larger welding line energy,And use cooling water type copper inch pad,The wire points to the copper side,and distance from the groove center5~6mm,The process parameters of common pure copper and stainless steel submerged arc welding are shown in the figure2。

brass tube and stainless steel fitting solution

(brass tube and stainless steel fitting solution)TIG welding(TIG)

When copper and its alloys are welded with stainless steel by argon tungsten arc welding,Good welded joints can be obtained,But to master the proper craftsmanship to get satisfactory results;The basic form of their welded joints has two butt joints and fillet joints.,No bevel on one side of copper,It is best to open half of the stainless steel sideVbevel。

Clean the surface of the weldment before welding,Coat the front and back with flux(70%H3BO3,21%Na2B4O2,9%CaF2),Welding after drying,Welding wire should use Monel alloy as much as possible(70%Ni,30%Cu),or copper alloy welding wire containing silicon and aluminum,Such as:HS221,QAl9-2,QAl9-4,QSi3-1,QSn4-3Wait;TIGWhen welding, the tungsten arc is biased to the copper side and the distance from the groove center is about5~8mm,To control the melting amount of stainless steel;Welding materials are mostly copper wire or copper-Nickel wire,Aluminium-containing bronze wire is also available,This is to improve the mechanical properties of the weld metal and prevent copper penetration cracks;Usually quick welding,The way of not swinging;When using argon arc welding-brazing process,Minimize the amount of melting on the stainless steel side,Equivalent to a brazed connection for stainless steel,For the copper side, it is a fusion welding connection。Brass and Stainless SteelTIGThe welding process parameters are shown in Fig.3。

brass tube and stainless steel fitting solution

gas welding

When copper and stainless steel are gas welded,Because the gas welding flame temperature is not as high as the arc temperature,May cause uneven melting of the base metal on both sides due to different melting points,Widening of the heat affected zone,Deformation increases,even not fused, etc.;Soldering pure copper with18-8when stainless steel,usually chooseHSCuZn-2,HSCuZn3,HSCuZnNiWaiting wire,use together301Solder powder(Brazing powder)Or borax welding with neutral flame;such as long welds,Before welding, a layer of brass can be surfacing on the groove surface of the stainless steel side,then solder。

(brass tube and stainless steel fitting solution)


When brazing copper and stainless steel,The solder used is mainly silver-based solder,Such asHL302,HL309,HL312Wait,The process method is similar to general brazing,It should be noted that the temperature of the stainless steel side should not be too high,When heating, the heat source is biased to the copper side。