41results about How to "Reduce weld cracking" patented technology

A method of laser welding for a steel sheet, in which there can be attained reduction of morphological defects of the weld area of welded material and exhibition of satisfactory bonding strength; and a laser welding apparatus therefor. There is provided a method of laser welding for a steel sheet through causing multiple steel sheets to abut on each other at end faces thereof and irradiating the abutted area of the steel sheets brought into mutual abuttal with laser beams to thereby weld the abutted area, comprising the cutting step of cutting end faces of steel sheets into forms suitable for mutual abuttal; the abutting step of bringing the end faces formed by the cutting step into mutual abuttal; the first heating step of heating the abutted area; and the laser welding step of welding by laser the abutted area having been heated by the first heating step.

The invention relates to the field of welding technologies, and discloses a manufacturing technology for a manhole well welding part. The manufacturing technology for the manhole well welding part comprises the technological steps of steel plate blanking, steel plate rolling, cylinder inner wall reinforcing by adopting an anti-deformation positioning tool, cylinder welding, anti-deformation positioning tool disassembling, flange machining, assembling, total welding and the like, wherein the anti-deformation positioning tool comprises four arc-shaped positioning blocks which jack the inner wallof a cylinder through helical jacking mechanisms and are evenly distributed in the circumferential direction of the inner wall of the cylinder, and the arc-shaped faces of the four arc-shaped positioning blocks make contact with the inner wall of the cylinder. According to the manufacturing technology for the manhole well welding part, welding deformation of the manhole well welding part is reduced, and the manufacturing precision of the manhole well welding part is improved.

The invention discloses a 7, 000-series alloy material for automobile bumpers. The 7, 000-series alloy material for the automobile bumpers is characterized in that the aluminum alloy comprises the alloy ingredients of Zn, Mg, Cu, Zr, Ti, Sn, Mn, Ag, Co, Sc, Yb, B, Cr4 and the balance aluminum and unavoidable impurities, wherein the ratio of Mg to Zn ranges from 0.17 to 0.19, the ratio of Cu to Mgranges from 0.43 to 0.53, the ratio of Cu to Ti ranges from 1.5 to 1.8, the content of one single impurity is smaller than or equal to 0.005%, the total content of the impurities is smaller than or equal to 0.1%, the average grain diameter of aluminum alloy grains ranges from 20 microns to 40 microns. When the alloy is observed through SEM and TEM, the area percentage of the strengthening phase MgZn2 ranges from 1% to 1.6% while the average size of the MgZn2 ranges from 50 nanometers to 60 nanometers, the area percentage of the strengthening phase Mg2Sn ranges from 0.3% to 0.6% while the average size of the Mg2Sn ranges from 30 nanometers to 50 nanometers, the area percentage of the strengthening phase Al6Mn ranges from 0.3% to 0.4% while the average size of the Al6Mn ranges from 20 nanometers to 30 nanometers, the area percentage of the strengthening phase Al3Ti ranges from 0.5% to 0.8% while the average size of the Al3Ti ranges from 20 nanometers to 30 nanometers, the yield strengthranges from 580 MPa to 650 Mpa, the tensile strength ranges from 670 MPa to 720 MPa, and the elongation ranges from 18% to 23%.

The invention proposes a welding process, which includes the following steps: using welding equipment to locate the first workpiece and the second workpiece; using swing welding at the two largest gap points between the circular end surface and the cylindrical peripheral surface; Select an arc starting point between the cylindrical peripheral surfaces, and the arc starting point corresponds to the position between the two maximum gap points on the corresponding circle of the circular end surface; the arc starting point is used for welding, and the welding equipment is used at the same time. The center line of the workpiece is the shaft synchronously rotating the first workpiece and the second workpiece counterclockwise. The welding process includes two weldings. The first welding adopts swing welding, and the second welding is performed immediately after the first welding. Through the above design, the present invention uses swing welding to replace the fixed position welding in the existing technology to weld the largest gap point, which can reduce welding cracks and lack of fusion caused by insufficient heat input and stress concentration during the welding process.

The invention discloses a furnace skin protecting and repairing method adopted after burning loss of a blast furnace cooling wall. The method comprises the following steps that according to the size of an area of damaged blast furnace skin, a manufactured cooling device is installed on the damaged blast furnace skin, then the damaged furnace skin is shifted and taken out or perforated, then furnace burden in the furnace is blocked and repair welding is conducted. According to the method, the cooling wall does not need to be replaced, only the cooling device which is simple in structural form is adopted, the structure of the cooling device is optimized, the cooling effect of the cooling device in a zone is improved, and heat shock in the furnace caused by falling of the cooling wall is madeup; and the repairing method can be used for repairing the furnace skin of the blast furnace on line, and the method is simple and feasible; the manufacturing cost is low, and particularly on the damaged blast furnace skin, five cooling plates are set in a group and are distributed in an X shape on the damaged furnace skin; and the X-shaped structure has the advantages that air flow and the furnace burden can be prevented from being shaken simultaneously, and the welding seam cracking phenomenon of the cooling device can be reduced.