High-strength Hull Structural Steel Welding Welding Crack Formation And Prevention

Along with the development of science and technology, the modem ships are getting more and more large. All kinds of great thickness higher strength hull structural steel plate are used more and more, along with the increase of the main dimension of the ship and the increase of proportion of big ship on gross. The different kinds of welding process that are aimed at the great thickness high strength hull-structure steel plate are also continuously developed in actual work .In order to meet the performance requirements of different kinds of great thickness high strength hull-structure steel in the ship's structures, the welding structure is also to develop to high parameter and more large. It need the weldability and welding procedure of high strength hull-structure steel to have not only the well mechanical property, but also the well processing property and still ought to have higher working efficiency moreover.The weldability of metal is introduced in the thesis, also the factors of affecting the weldability of metal are analyzed. The test methods of weldability of metal are introduced in the thesis, and the test methods in common use in the field of engineering are also introduced in the thesis. In addition, aiming at technology request of welding procedure of great thickness high strength hull-structure steel plate and research of welding processes, the test methods of weldability of metal which comply with China Classification Society(CCS) are introduced in the thesis.The harm of weld crack is also introduced in the thesis, and the weld crack is classed and analyzed. The hot crack and cold crack is analyzed in detail during the welding of great thickness high strength hull-structure steel plate. Crack's character and crack's classes are respectively researched and expounded deeply, especially cracks' forming mechanism and factors causing cracks are emphasized in the thesis.