A method for analysing the quality of a weld bead in a welding zone using a thermal camera. A thermal image (IMG) of a given area is divided into a plurality of sub-areas each having a respective temperature (Ti). During a learning step, the temperature evolution (Ti(t)) of each sub-area is monitored for different welding conditions. During a training step, the temperature evolutions (Ti(t)) are processed for training a classifier (304). For this purpose, a respective cooling curve is extracted (302) from each temperature evolution (Ti(t)), and parameters (F) are determined that identify the shape of each cooling curve. The parameters (F) are used as input features for the classifier (304). In normal operation the temperature evolution (Ti(t)) of each sub-area (Ai) is monitored and the classifier (304) estimates weld quality (S).

A method for analysing the quality of a weld bead in a welding zone using a thermal camera. A thermal image (IMG) of a given area is divided into a plurality of sub-areas each having a respective temperature (Ti). During a learning step, the temperature evolution (Ti(t)) of each sub-area is monitored for different welding conditions. During a training step, the temperature evolutions (Ti(t)) are processed for training a classifier (304). For this purpose, a respective cooling curve is extracted (302) from each temperature evolution (Ti(t)), and parameters (F) are determined that identify the shape of each cooling curve. The parameters (F) are used as input features for the classifier (304). In normal operation the temperature evolution (Ti(t)) of each sub-area (Ai) is monitored and the classifier (304) estimates weld quality (S).

A weld inspection apparatus that detects a weld defect in a welded portion of metal plates and includes a liquid application head disposed over one side surface of the metal plates and capable of moving in a welding direction of the metal plates, and an air jet head disposed over another side surface of the metal plates and capable of moving in the welding direction of the metal plates. The liquid application head includes a liquid application nozzle that projects toward the one side surface of the metal plates and applies liquid for sealing the welded portion. The air jet head includes an air jet nozzle that projects toward the another side surface of the metal plates and discharges air toward the welded portion to which the liquid has been applied.

A weld inspection apparatus that detects a weld defect in a welded portion of metal plates and includes a liquid application head disposed over one side surface of the metal plates and capable of moving in a welding direction of the metal plates, and an air jet head disposed over another side surface of the metal plates and capable of moving in the welding direction of the metal plates. The liquid application head includes a liquid application nozzle that projects toward the one side surface of the metal plates and applies liquid for sealing the welded portion. The air jet head includes an air jet nozzle that projects toward the another side surface of the metal plates and discharges air toward the welded portion to which the liquid has been applied.

The present invention discloses a quantitative evaluation method for sensitivity of welding transverse cold cracks in a typical joint of a jacket, including following steps: S1, performing macroscopic analysis, metallographic analysis, fracture analysis and hardness analysis on cracks of a failed component to obtain main causes of cold crack failure; and S2, designing and processing a dedicated sample, and performing rigid restraint crack tests on the dedicated sample at different preheating temperatures to obtain a cracking/non-cracking critical restraint stress σ1cr of the sample. According to the method, a rigid restraint crack test is applied to evaluation of sensitivity of welding transverse cracks, so that external restraint conditions borne by a welding joint can be accurately simulated, a stress state of the welding joint in an actual working condition can be truly reflected, the overall evaluation precision is greatly improved, and a foundation is laid for accurately evaluating sensitivity of welding cold cracks in a tube joint. Furthermore, a welding technology (base material, welding material, welding process and restraint level) is designed to restrain cold cracks from cracking, and the method has important theoretical significance and engineering value.

The present invention discloses a quantitative evaluation method for sensitivity of welding transverse cold cracks in a typical joint of a jacket, including following steps: S1, performing macroscopic analysis, metallographic analysis, fracture analysis and hardness analysis on cracks of a failed component to obtain main causes of cold crack failure; and S2, designing and processing a dedicated sample, and performing rigid restraint crack tests on the dedicated sample at different preheating temperatures to obtain a cracking/non-cracking critical restraint stress σ1cr of the sample. According to the method, a rigid restraint crack test is applied to evaluation of sensitivity of welding transverse cracks, so that external restraint conditions borne by a welding joint can be accurately simulated, a stress state of the welding joint in an actual working condition can be truly reflected, the overall evaluation precision is greatly improved, and a foundation is laid for accurately evaluating sensitivity of welding cold cracks in a tube joint. Furthermore, a welding technology (base material, welding material, welding process and restraint level) is designed to restrain cold cracks from cracking, and the method has important theoretical significance and engineering value.

A system for inspecting a reflective surface includes a first imaging assembly configured to take a first image of the reflective surface, the first image including depth information, a second imaging assembly configured to take a second image of the reflective surface, the second image including contrast information, and a processor configured to acquire the first image and the second image. The processor is configured to perform: estimating a depth profile of the surface based on the depth information, correlating the depth profile with the second image, and identifying a feature of the reflective surface based on the correlation.

A system for inspecting a reflective surface includes a first imaging assembly configured to take a first image of the reflective surface, the first image including depth information, a second imaging assembly configured to take a second image of the reflective surface, the second image including contrast information, and a processor configured to acquire the first image and the second image. The processor is configured to perform: estimating a depth profile of the surface based on the depth information, correlating the depth profile with the second image, and identifying a feature of the reflective surface based on the correlation.

A method for inspecting a welding defect of the present invention includes: a threshold resistance setting step (S100) of measuring a resistance of a welded portion of a sample group and deriving a threshold resistance value which becomes an evaluation standard of a weak welding; a resistance measuring step (S200) of measuring a resistance value of a welded portion to be inspected; and a step (S300) of determining as a weak welding if the resistance value measured in the resistance measuring step exceeds the threshold resistance value, wherein the threshold resistance setting step (S100) and the resistance measuring step (S200) include measuring a resistance using a microresistance measuring instrument having a resolution of nanoohm to microohm units.

The welding defect inspection method of the present invention shows excellent detection power for the welding defect by a weak welding.

A bead appearance inspection device includes an input unit configured to enter input data related to a welding bead of a workpiece produced by welding, and a determination unit configured to perform an inspection determination related to a shape of the welding bead based on the input data. The determination unit determines which of a range of a value indicating a non-defective product zone, a range of a value indicating a gray zone, and a range of a value indicating a defective product zone a value obtained from the input data belongs to. The range of the value indicating the gray zone is between the range of the value indicating the non-defective product zone and the range of the value indicating the defective product zone.