A spot welded joint of at least two steel sheets is provided. At least one of the steel sheets presents yield strength above or equal to 600 MPa, an ultimate tensile strength above or equal to 1000 MPa, uniform elongation above or equal to 15%. The base metal chemical composition includes 0.05≤C≤0.21%, 4.0≤Mn≤7.0%, 0.5≤Al≤3.5%, Si≤2.0%, Ti≤0.2%, V≤0.2%, Nb≤0.2%, P≤0.025%, B≤0.0035%, and the spot welded joint contains a molten zone microstructure containing more than 0.5% of Al and containing a surface fraction of segregated areas lower than 1%, said segregated areas being zones larger than 20 μm.sup.2 and containing more than the steel nominal phosphorus content.

A spot welded joint of at least two steel sheets is provided. At least one of the steel sheets presents yield strength above or equal to 600 MPa, an ultimate tensile strength above or equal to 1000 MPa, uniform elongation above or equal to 15%. The base metal chemical composition includes 0.05≤C≤0.21%, 4.0≤Mn≤7.0%, 0.5≤Al≤3.5%, Si≤2.0%, Ti≤0.2%, V≤0.2%, Nb≤0.2%, P≤0.025%, B≤0.0035%, and the spot welded joint contains a molten zone microstructure containing more than 0.5% of Al and containing a surface fraction of segregated areas lower than 1%, said segregated areas being zones larger than 20 μm.sup.2 and containing more than the steel nominal phosphorus content.

The present invention provides a process for suppressing abnormal grain growth in friction stir welded aluminum alloys by inserting an intermediate annealing treatment (“IAT”) after the welding step on the article. The IAT may be followed by a solution heat treatment (SHT) on the article under effectively high solution heat treatment conditions. In at least some embodiments, a deformation step is conducted on the article under effective spin-forming deformation conditions or under effective superplastic deformation conditions. The invention further provides a welded article having suppressed abnormal grain growth, prepared by the process above. Preferably the article is characterized with greater than about 90% reduction in area fraction abnormal grain growth in any friction-stir-welded nugget.

The present invention provides a process for suppressing abnormal grain growth in friction stir welded aluminum alloys by inserting an intermediate annealing treatment (“IAT”) after the welding step on the article. The IAT may be followed by a solution heat treatment (SHT) on the article under effectively high solution heat treatment conditions. In at least some embodiments, a deformation step is conducted on the article under effective spin-forming deformation conditions or under effective superplastic deformation conditions. The invention further provides a welded article having suppressed abnormal grain growth, prepared by the process above. Preferably the article is characterized with greater than about 90% reduction in area fraction abnormal grain growth in any friction-stir-welded nugget.

A method of manufacturing a cutting member include cutting a first metal material to form a first portion of the cutting member; cutting second metal material to form a second portion of the cutting member, wherein a first edge of the second portion has at least two line segments, a curve formed by the at least two line segments being mathematically continuously differentiable; welding the first portion and the second portion together; raising the cutting member blank to a first temperature at a first rate and holding raising the cutting member blank from the first temperature to a second temperature at a second rate lower than the first rate and holding, and raising the cutting member blank from the second temperature to a third temperature at a third rate not higher than the second rate and holding.

A method of manufacturing a cutting member include cutting a first metal material to form a first portion of the cutting member; cutting second metal material to form a second portion of the cutting member, wherein a first edge of the second portion has at least two line segments, a curve formed by the at least two line segments being mathematically continuously differentiable; welding the first portion and the second portion together; raising the cutting member blank to a first temperature at a first rate and holding raising the cutting member blank from the first temperature to a second temperature at a second rate lower than the first rate and holding, and raising the cutting member blank from the second temperature to a third temperature at a third rate not higher than the second rate and holding.

A method is provided for determining whether post-weld heat treatments should be required for external attachment welds in applications where stress corrosion cracking is a possibility. According to the method, residual stress values are measured in test samples welded at high input heat levels and test samples welded at low input heat levels for a variety of different wall thickness. A threshold residual stress level is determined according to a method of selecting a common pipe used in industry and measuring the residual stress level in the longitudinal seam of the pipe. The measured residual stress values for the high and low heat input welds are compared against the threshold to determine whether for a particular wall thickness, the high and low input data exceeds the threshold, indicating whether post-weld heat treatments are required.

An approach to provide an electronic assembly process that includes receiving at least one electronic assembly after a solder reflow process using a Sn-containing solder and a water-soluble flux. The approach includes baking the at least one electronic assembly in an oxygen containing environment and, then cleaning the at least one electronic assembly in an aqueous cleaning process.

A method of reworking an aerospace component includes removing a casting defect from a component manufactured of a non-fusion weldable base alloy to form a cavity. The cavity is then at least partially filled with a multiple of layers of discrete laser powder deposition spots of a filler alloy. A cast component for a gas turbine engine includes a cast component non-fusion weldable base alloy with a cavity filled with a multiple of layers of laser powder deposition spots of a filler alloy. The filler alloy may be different than the non-fusion weldable base alloy. A layer of non-fusion weldable base alloy is at least partially within the cavity and over the filler alloy.

Disclosed are a pressure vessel steel sheet and a method for manufacturing the same, the steel sheet comprising: by wt %, 0.10-0.20% of C, 0.15-0.40% of Si, 1.15-1.50% of Mn, 0.45-0.60% of Mo, 0.03-0.30% of Cu, 0.025% or less of P, 0.025% or less of S and 0.005-0.06% of sol. Al; two or more selected from the group consisting of 0.03-0.30% of Cr, 0.002-0.025% of Nb and 0.002-0.025% of Zr, and the balance of Fe and inevitable impurities, wherein the structure comprises a mixture structure of ferrite, perlite and tempered bainite after post weld heat treatment (PWHT) for 60 hours at 600-660° C., and the area fraction of the tempered bainite is at least 10% (excluding 100%).