Application Of Phased Array Technology In The Inspection Of Ship Welding Structure

Welding has been used in shipbuilding industry for a long time because of its high mechanical property,high production efficiency and good sealing performance.But defects formed inside and on surface during hull steel welding seriously affect mechanical properties so that cause safety problems during ships' navigation.Phased array ultrasonic testing technology could test the whole section of weld seam by adjusting the sound beam angle and focus depth.For its advantages of efficiency,accuracy and audio-visual display,it has been used in various industries including petrol,electric and space industry.However,due to the particularity of ship structure,the application of phased array ultrasonic testing technology started late and developed slow in ship manufacturing.In order to increase efficiency and reduce cost,phased array ultrasonic testing technology is imperative to use to control the welding quality during the shipbuilding process.This article describes designing on detections of different situations in several common welding methodology,such like weld seam containing crack,incomplete penetration,lack of fusion,porosity and slag.Firstly,the test plates were photographed using radiographic testing,and the length of the defect was measured and quantified.Then the conventional ultrasonic testing was used to scan the test plates and measure the length and quantify the defect.Finally,the test plates were scanned with phased array ultrasonic,and the image and data of the phased array detection were obtained.Combining different scan patterns with 3D display of weld seam images,the images characteristics of different typical defects in the phased array ultrasonic testing are studied,the article indicates that the typical defects obtained by phased array ultrasonic testing are highly coincided with the radiographic testing results.The article also summarized five typical characteristics of weld defects in the shipyard welding.And through the actual inspection and testing in the shipyard,the reliability of phased array ultrasonic testing has been verified,which provided strong support and assistance for phased array ultrasonic testing in the shipbuilding industry.