Research Of Production Process For 36kg High Strength Ship Plate

With the widen and heavy plate production lines are put into produce gradually, as well as proposed by the state that build the widen and heavy plate production lines into the world's high-grade, quality timber production basement plans into implementation stage, the plate enterprises are increasing high value-added plates' research and production, and high-strength ship plate is one of them. The research of this paper is under the background of the Shouqin Metal Material Co. Ltd. certification of high strength ship plate's 9 countries classification societies process. The main work and results are as follows:1.Based on the several times rolling experiments in plant, we researched the relationships between the mechanical properties and the chemical composition, heating process, start rolling temperature, finishing temperature, finish rolling temperature, finish cooling temperature and cooling rate, then get the optimized production technology for high strength ship plate:initial rolling temperature is higher than 1050℃, finish rolling initial temperature 850±20℃, finish rolling 820～860℃, the best temperature is 840℃, finish rolling temperature 660-680℃and cooling rate 5～9℃/s. The temperature holding thickness are differences in different thickness, for 30mm plates, the thickness of temperature holding is 3 times the plates, and for 50mm plates is twice. Using the technology to help the enterprise companies successfully passed certification classification societies.2. By metallography, SEM and EDS, fracture morphology, inclusions and microstructure have been studied. Compare the result of laminar samples and not laminar we can obvious found:the higher proportion of pearlite in the center area of the thickness direction is the reason for the rock-candy structure appeared at the center of the tensile sample which caused crack and finally caused the fault mechanical. Increasing the temperature and holding time of reheating, the slabs'keep 3. Using black box experiment record the heating process of the slab in the furnace we get that after 186min reheating, the core temperature of 250mm slab reach 1200℃, which is get the set temperature of furnace, but there are also have 15℃thermoelectric along the thickness, the temperature in watermark of fixed beam is lower 50-60℃than others. With the relationship of heat system and laminar crack, amend the heat system of slab for different composition.4. Analysis of the effect of different normalizing temperature and the holding times of high strength ship plate on the microstructure and mechanical properties. Also, we get the normalizing process for fault mechanical properties plates due to various factors when the manufacture process. After 920℃normalizing and keep 1min/mm×H can get the optimization mechanical, also, with 950℃normalizing can completely eliminate tensile samples'laminar crack.