Research And Manufacturing And Application Of The Multitype-anvil In Slab Sizing Press

Sizing press, which contributes to improvement of the level of the incorporation of casting and rolling, was one of the technologies in adjusting casting slabs width on the rolling product line. Because of the working condition of the slab sizing press (ssp) anvil, the number of cracks on the working surface of ssp anvils was large, which had been regarded as the potential danger to their service lifetime and the steel rolling industry.For the high price of imported anvils and the limited service lifetime of the domestic ones, in this thesis, the way of strypped-down and self-research and development would be adopted. With isolated studies in the lab, the computer simulating and field tests, the method of surfacing welding had initially been used domestically in order to increase the service lifetime and lower the cost of the anvils.In the aspect of strypped-down, Fe-based build-up welding rod in the slab sizing press had been investigated using the mechanical properties, high temperature hardness and anti-impact testing and the microstructure observation of the overlay. It showed that the mechanical property, hardness and anti-impact property of the anvil were superior to those without using this build-up welding rod; In the top of the overlay, tempered sorbite, pro-eutectoid ferrite, and spherical carbide had been observed; in the bottom, tempered martensite and sorbite had been observed, respectively. In the aspect of self-research and development, a kind of Ni-based super alloy build-up welding rod had been used to improve the service lifetime of the anvil in the slab sizing press. The mechanical properties, high temperature hardness, the microstructure observation of the overlay and the macrostructure and the anti-impact property of the samples had been investigated. The results indicated that in the Ni-based surfacing welding layer, there were sheets ofγ′, which were regarded as the main strengthening phase of super alloys; the carbide of dispersion in the Ni-based surfacing welding layer played a positive role of improving the hardness of the Ni-based surfacing welding layer, which, at the mean time, owned ruptures of"quasi-cleavage+dimple".Comparison of thermal fatigue analysis between the two kind of surface welding rods-- Fe-based and Ni-base rod--applying to slab sizing press anvil had been made with help of the thermal fatigue test-bed researched and developed by Baosteel.Co, Ltd. The results told us that their cracking characterized as cracks along grain boundaries mainly, while a few of them were transcrystalline cracks; according to the investigation to the foreign impurity by SEM, comparison between the two kind of surface welding rods mentioned above had been completed; The ranking of the specimens with two kinds of surface welding rod had been assessed according to Uddeholm Criterion Map.With the help of the simulating software ANSYS, the verification of the results of thermal fatigue had been made.Comparison about the condition of the working surfaces of the two kinds of anvils with Fe-based and Ni-based surface welding layer, the imported ones and the domestic ones were to made when the anvils had finished sizing 30,000, 150,000, 200,000 ton of slabs, respectively. It could be concluded that comparing to domestic anvils, the anvils used experimental surfacing welding rods obtained a longer service lifetime, and the cost had been sharply cut down, by contrast to the imported anvils.