Summary of the invention
The objective of the invention is to solve the electron beam welding of TiAl/TC4 foreign material and be easy to generate macroscopical cold crack problem.
TiAl/TC4 foreign material electron beam welding thermal cycle composite control method, its welding object is two plate objects that thickness is 0.8mm~5.0mm, concrete steps are:
Step 1, the TiAl that will remove internal stress, the smooth cleaning of surface to be welded and TC4 sheet material are fixed a thermal insulation board respectively before fixing with anchor clamps between welding machine clamp base and each welding object;
Step 2, welding object implement is clamped, described anchor clamps only apply clamping force in the direction parallel with weld seam of welding object;
Step 3,5 * 10
-2Pa to 5 * 10
-4Under the atmospheric pressure of Pa, employing defocuses butt welded seam and peripheral part carries out the shuttle-scanning preheating, and accelerating potential is 50kV~55kV, and focus current 3370mA, line are 2mA~12mA, and sweep speed is 2mm/s~10mm/s;
Step 4, step 3 are welded after finishing immediately, and accelerating potential is identical with step 3, and focus current is 2590mA, and line is 3mA~50mA, and speed of welding is 2mm/s~15mm/s;
After step 5, step 4 were finished, employing immediately defocused butt welded seam and carries out after heat, and accelerating potential is identical with step 3, and focus current is 3370mA, and line is 12mA~1mA, and sweep speed is 2mm/s~20mm/s.
When welding object is two thickness when being the plate object of 0.8mm~2.0mm, its welding method is:
Step 1, the TiAl that will remove internal stress, the smooth cleaning of surface to be welded and TC4 sheet material are fixed a thermal insulation board respectively before fixing with anchor clamps between welding machine clamp base and each welding object;
Step 2, welding object implement is clamped, described anchor clamps only apply clamping force in the direction parallel with weld seam of welding object;
Step 3,5 * 10
-2Pa to 5 * 10
-4Under the atmospheric pressure of Pa, adopt to defocus place to be welded is carried out shuttle-scanning, two-stage preheating, every grade of line that adopts 2mA respectively scans the other end from an end of weld seam; Accelerating potential is 50kV~55kV, focus current 3370mA, and sweep speed is 2mm/s~10mm/s;
Step 4, step 3 are welded after finishing immediately, and accelerating potential is identical with step 3, and focus current is 2590mA, adopt the line of 2mA~8mA, the speed of welding of 5mm/s~15mm/s that the welding position is welded;
After step 5, step 4 are finished, adopt immediately to defocus butt welded seam and carry out the level Four after heat, every grade of line that adopts 4mA, 4mA, 2mA, 2mA respectively scans the other end from an end of weld seam, and accelerating potential is identical with step 3, focus current is 3370mA, and sweep speed is 2mm/s~20mm/s.
TiAl/TC4 foreign material electron beam welding thermal cycle composite control method, its welding object is the thick tubing for the TiAl of 0.8mm~3.5mm and TC4 of two endwalls, and the weld seam of welding is a circular weld, and concrete steps are:
Step 1, will remove internal stress, the smooth cleaning of surface to be welded two welding objects with anchor clamps fixing before, fixing thermal insulation board between anchor clamps and welding object;
Step 2, welding object implement is clamped, described anchor clamps adopt the mode that axially clamps to welding object;
Step 3,5 * 10
-2Pa to 5 * 10
-4Under the atmospheric pressure of Pa, adopt to defocus place to be welded and adjacent regions thereof are carried out the multiple scanning preheating, accelerating potential is 50kV~55kV, and focus current 3350mA, line are 2mA~10mA, and sweep speed is 2mm/s~8mm/s.
Step 4, step 3 are welded after finishing immediately, and accelerating potential is identical with step 3, and focus current is 2590mA, and line is 2mA~32mA, and speed of welding is 2mm/s~10mm/s;
After step 5, step 4 were finished, the weld seam that welding is finished carried out after heat immediately, and employing defocuses butt welded seam and carries out multiple scanning, accelerating potential is identical with step 3, focus current is 3350mA, and line is between 10mA~2mA, and sweep speed is 2mm/s~12mm/s.
When welding object is a pipe thickness when being the TiAl of 0.8mm~1.5mm and TC4 tubing, its concrete welding method is:
Step 1, will remove internal stress, the smooth cleaning of surface to be welded two welding objects with anchor clamps fixing before, fixing thermal insulation board between anchor clamps and welding object;
Step 2, welding object implement is clamped, described anchor clamps adopt the mode that axially clamps to welding object;
Step 3,5 * 10
-2Pa to 5 * 10
-4Under the atmospheric pressure of Pa, adopt to defocus place to be welded is carried out multiple scanning, secondary preheating, every grade of line that all adopts 2mA is around the circular weld run-down; Accelerating potential is 50kV~55kV, focus current 3350mA, and sweep speed is 2mm/s~8mm/s;
Step 4, step 3 are welded after finishing immediately, and accelerating potential is identical with step 3, and focus current is 2590mA, adopt the line of 2mA~8mA to weld; Speed of welding is 2mm/s~10mm/s;
After step 5, step 4 are finished, the weld seam that welding is finished adopts to defocus and carries out the level Four after heat immediately, every grade of line that adopts 4mA, 2mA, 2mA, 2mA respectively is around the circular weld run-down, accelerating potential is identical with step 3, focus current is 3350mA, and sweep speed is 2mm/s~12mm/s.
When welding object is a pipe thickness when being the TiAl of 2.0mm~3.5mm and TC4 tubing, its welding method is:
Step 1, will remove internal stress, the smooth cleaning of surface to be welded two welding objects with anchor clamps fixing before, fixing thermal insulation board between anchor clamps and welding object;
Step 2, welding object implement is clamped, described anchor clamps adopt the mode that axially clamps to welding object;
Step 3,5 * 10
-2Pa to 5 * 10
-4Under the atmospheric pressure of Pa, employing defocuses carries out multiple scanning, level Four preheating to place to be welded, every grade is all adopted the line of 2mA, 2mA, 4mA, 6mA is 50kV~55kV around circular weld run-down accelerating potential, focus current 3350mA, and sweep speed is 2mm/s~8mm/s;
Step 4, step 3 are welded after finishing immediately, and accelerating potential is identical with step 3, and focus current is 2590mA, adopt the line of 10mA~32mA to weld; Speed of welding is 2mm/s~10mm/s;
After step 5, step 4 are finished, the weld seam that welding is finished adopts to defocus and carries out six grades of after heat immediately, every grade of line that adopts 6mA, 5mA, 4mA, 3mA, 2mA, 2mA respectively is around the circular weld run-down, accelerating potential is identical with step 3, focus current is 3350mA, and sweep speed is 2mm/s~12mm/s.
The composition of described TiAl intermetallic compound comprises: Ti:48~65at.%, Al:35~51at.%, also comprise V:1.0~9.0at.% or Cr:1.5~2.5at.% or Nb:1.5~5.0at.%, described TC4 is the alpha-beta Type Titanium Alloy, and nominal composition is Ti-6Al-4V.
TiAl/TC4 foreign material electron beam welding thermal cycle composite control method of the present invention, do not need to increase special installation or add the transition zone metal, just can avoid weld seam to produce macroscopic cracking fully, reach the purpose of flawless welding, be applicable to the welding of TiAl/TC4 foreign material various terminal form.
The specific embodiment
The specific embodiment one: TiAl/TC4 foreign material electron beam welding thermal cycle composite control method, its welding object is two plate objects that thickness is 0.8mm~5.0mm, concrete steps are:
Step 1, the TiAl that will remove internal stress, the smooth cleaning of surface to be welded and TC4 sheet material are fixed a thermal insulation board respectively before fixing with anchor clamps between welding machine clamp base and each welding object;
Step 2, welding object implement is clamped, described anchor clamps only apply clamping force in the welding object direction parallel with weld seam;
Step 3,5 * 10
-2Pa to 5 * 10
-4Under the atmospheric pressure of Pa, employing defocuses carries out shuttle-scanning, classification preheating to place to be welded, each grade adopts the line that increases progressively successively from small to large among 2mA~12mA to scan the other end from an end of weld seam respectively, accelerating potential is 50kV~55kV, focus current 3370mA, sweep speed is 2mm/s~10mm/s;
Step 4, step 3 are welded after finishing immediately, and accelerating potential is identical with step 3, and focus current is 2590mA, and line is 3mA~50mA, and speed of welding is 2mm/s~15mm/s;
After step 5, step 4 are finished, employing immediately defocuses butt welded seam and carries out the classification after heat, each grade adopts the line that successively decreases successively from big to small among 12mA~1mA to scan the other end from an end of weld seam respectively, accelerating potential is identical with step 3, focus current is 3370mA, and sweep speed is 2mm/s~20mm/s.
The composition of the described TiAl intermetallic compound of present embodiment comprises: Ti:48~65at.%, Al:35~51at.%, can also comprise V:1.0~9.0at.% or Cr:1.5~2.5at.% or Nb:1.5~5.0at.%, described TC4 is the alpha-beta Type Titanium Alloy, and nominal composition is Ti-6Al-4V.
In the step 1 in the present embodiment, before clamping, between welding machine clamp base and each welding object, fix a thermal insulation board respectively,, reduce the cooling velocity of postwelding joint in order to the conduction of the heat between restriction welding object and the anchor clamps.
In the step 2 of present embodiment, only adopt the mode that applies clamping force in the welding object direction parallel to be fixedly clamped with weld seam, in order to of the thermal expansion of constraint thermal cycle heating period welding object along bead direction, reduce the thermic stress that welding object produces at the thermal cycle cooling stage, and do not apply contained in other directions, avoided the thermal cycle cooling stage to produce bigger constraint stress effectively, the generation that prevents macroscopic cracking has been had certain effect.
The step 3 to five of present embodiment, the thermal cycle that divides three phases programming continuous control whole welding process, in the warm of step 2, adopt the classification preheating, increase line step by step, can make that the temperature at position rises gradually around the weld seam, after the step 5 after welding in the thermal process, employing classification after heat, the line that successively decreases step by step can make weld seam after the welding and temperature on every side thereof descend gradually.Adopt the welding method of present embodiment, weld metal alloying element in slow cooling procedure is more fully spread,, can obtain seam organization relatively uniformly for changing mutually and separating out the time limit that provides sufficient; Distortional stress and crystalline stress are slowly discharged, help heat stress value is reduced to the tensile strength that is lower than weld seam, thereby avoided the generation of welding cold cracking effectively.
The specific embodiment two: the thickness of the welding object of present embodiment is 2.0mm~3.0mm, and the difference of the welding method and the specific embodiment one is,
In the warm of step 3, adopt the level Four preheating, every grade of line that adopts 2mA, 4mA, 6mA and 8mA respectively scans the other end from an end of weld seam;
In step 4, adopt the line of 16mA~32mA, the speed of welding of 5mm/s~10mm/s to weld;
In the back thermal process of step 5, adopt the level Four after heat, every grade of line that adopts 8mA, 6mA, 4mA, 2mA respectively scans the other end from an end of weld seam.
The specific embodiment three: the difference of the present embodiment and the specific embodiment one is that the thickness of institute's welding object is 0.8mm~2.0mm, and the difference of the welding method and the specific embodiment one is,
In the warm of step 3, adopt the two-stage preheating, every grade of line that adopts 2mA respectively scans the other end from an end of weld seam;
In step 4, adopt the line of 2mA~8mA, the speed of welding of 5mm/s~15mm/s that the welding position is welded;
In the back thermal process of step 5, adopt the level Four after heat, every grade of line that adopts 4mA, 4mA, 2mA, 2mA respectively scans the other end from an end of weld seam.
The specific embodiment four: the difference of the present embodiment and the specific embodiment one is that the thickness of institute's welding object is 3.0mm~5.0mm, and the difference of the welding method and the specific embodiment one is,
In the warm of step 3, adopt six grades of preheatings, every grade of line that adopts 2mA, 4mA, 6mA, 8mA, 9mA, 10mA respectively scans the other end from an end of weld seam;
In step 4, adopt the line of 24mA~50mA that the welding position is welded, speed of welding is 2mm/s~10mm/s;
In the back thermal process of step 5, adopt six grades of after heat, every grade of line that adopts 10mA, 9mA, 8mA, 6mA, 4mA, 2mA respectively scans the other end from an end of weld seam.
The specific embodiment five: the material composition of the heat insulation backing plate described in the specific embodiment one described step 1 is silica and silicate.
The good heat-insulation effect of the heat insulation backing plate of present embodiment, can prevent effectively that the heat that produces owing to welding on the soldered object is transmitted on the welding machine clamp base, reduced the loss of energy on the one hand, also prevented on the other hand because the heat of welding machine clamp base causes the joint cooling velocity to increase.
The specific embodiment six: the difference of the present embodiment and the specific embodiment one to five is, after step 5 is finished, carries out the technology of step 6, stress relief annealing, and welding object is heated to 900 ℃, and insulation 10h cools off with stove then.
The specific embodiment seven: to be that two endwalls are thick be the TiAl of 0.8mm~3.5mm and TC4 tubing for TiAl/TC4 foreign material electron beam welding thermal cycle composite control method, its welding object, and the weld seam of welding is a circular weld, and concrete steps are:
Step 1, will remove internal stress, the smooth cleaning of surface to be welded two welding objects with anchor clamps fixing before, fixing thermal insulation board between anchor clamps and welding object;
Step 2, welding object implement is clamped, described anchor clamps adopt the mode that axially clamps to welding object;
Step 3,5 * 10
-2Pa to 5 * 10
-4Under the atmospheric pressure of Pa, adopt to defocus and treat weld seam and carry out multiple scanning, classification preheating, each grade adopts the line that increases progressively successively from small to large among 2mA~10mA around the circular weld run-down respectively; Accelerating potential is 50kV~55kV, focus current 3350mA, and sweep speed is 2mm/s~8mm/s;
Step 4, step 3 are welded after finishing immediately, and accelerating potential is identical with step 3, and focus current is 2590mA, and line is 2mA~32mA, and speed of welding is 2mm/s~10mm/s;
After step 5, step 4 are finished, the weld seam that welding is finished adopts to defocus and carries out the classification after heat immediately, each grade adopts the line that successively decreases successively from big to small among 10mA~2mA around the circular weld run-down respectively, accelerating potential is identical with step 3, focus current is 3350mA, and sweep speed is 2mm/s~12mm/s.
The composition of the described TiAl intermetallic compound of present embodiment comprises: Ti:48~65at.%, Al:35~51at.%, can also comprise V:1.0~9.0at.% or Cr:1.5~2.5at.% or Nb:1.5~5.0at.%, described TC4 is the alpha-beta Type Titanium Alloy, and nominal composition is Ti-6Al-4V.
In the step 1 of present embodiment, between anchor clamps and each welding object, fix a thermal insulation board respectively,, reduced the cooling velocity of postwelding joint effectively in order to the conduction of the heat between restriction welding object and the anchor clamps.
In the step 2 of present embodiment, only fix, and do not apply containedly in other directions, avoided the thermal cycle cooling stage to produce bigger constraint stress effectively in the clamping force that axially applies of welding object.
Present embodiment makes the slow transition of heat balance of welding process from the thermal cycle of step 3 to five minute three phases programming continuous control whole welding process, prevents the sudden change of welding process temperature, has prevented the generation of macroscopic cracking effectively.
The specific embodiment eight: the pipe thickness of the welding object of present embodiment is 0.8mm~1.5mm, is with the difference of the specific embodiment seven described methods,
In the warm of step 3, adopt the secondary preheating, every grade of line that all adopts 2mA is around the circular weld run-down;
In step 4, adopt the line of 2mA~8mA to weld;
In the back thermal process of step 5, adopt the level Four after heat, every grade of line that adopts 4mA, 2mA, 2mA, 2mA respectively is around the circular weld run-down.
The specific embodiment nine: the pipe thickness of the welding object of present embodiment is 2.0mm~3.5mm, is with the difference of the specific embodiment eight described methods,
In the warm of step 3, adopt the level Four preheating, every grade of line that all adopts 2mA, 2mA, 4mA, 6mA is around the circular weld run-down;
In step 4, adopt the line of 10mA~32mA to weld;
In the back thermal process of step 5, adopt six grades of after heat, every grade of line that adopts 6mA, 5mA, 4mA, 3mA, 2mA, 2mA respectively is around the circular weld run-down.
The specific embodiment ten: in the specific embodiment seven to nine, after step 5, increase step 6, stress relief annealing technology, welding object is heated to 900 ℃, insulation 10h cools off with stove then.