32results about How to "Reduce internal cracks" patented technology

There is provided a method for producing a Cu—Ni—Sn alloy by a continuous casting method or a semi-continuous casting method, the method including pouring a molten Cu—Ni—Sn alloy from one end of a mold, both ends of which are open, and continuously drawing out the alloy as an ingot from the other end of the mold while solidifying a part of the alloy, the part being near the mold; and spraying mist-like liquid on the drawn-out ingot to cool the ingot, thereby making a cast product of the Cu—Ni—Sn alloy.

A periodic tube rolling machine with slant rolling drill rig is used to generate big caliber thick wall steel blocks, to satisfy the inside and surface quality requirements. Inner cavity working section of the mold is wave shape multilateral cross section shape wave ingot mold, with sulfur content controlled under 0.025% of the steel liquid, casting temperature within 40 to 80DEG C, linear speed 80 to 230mm / min, cracking ratio lower than 5%, pass rate 98.81%, with low consumption of metal, low cost, especially suitable for rolling into seamless steel tubes with multi types and specification and phi> / =426mm.

The invention discloses a Phi 500-650mm Cr6 type forged-electroslag-steel cold-rolled work roll blank forging and deforming technology. The technology includes the steps of converter producing plus LF refining plus VD vacuuming, continuous casting of round blank, hot annealing of electronic blank, clearing, electroslag remelting, annealing of electroslag ingot, forging and annealing after forging, wherein four-fire mode production is adopted in forging, upsetting and drawing out deformation methods are adopted in the first fire time, forging under great pressure is adopted in the second fire time, and forging to forming in the third and fourth fire time. Temperature and heat preservation time in high-temperature diffusion are key to control in forging, furnace return temperature and time in each fire time of forging and deformation and final forging temperature of each fire time are controlled. The spheroidized structure of the produced Cr6 type forged-electroslag-steel cold-rolled work roll blank is 2-3 in grade, carbide mesh is less than or equal to 2.0 in grade, carbide strap and liquation are below 1.0 in grade, total non-metallic inclusions is less than or equal to 2.0 in grade, flaw detection eligibility rate is increased from original 75% to 95%, carbide distribution is small and diffused, and long service life is achieved.

The invention discloses a heat preservation layer structure for disposable anti-dismantling chemical equipment, and belongs to the field of chemical equipment. The heat preservation layer structure for the disposable anti-dismantling chemical equipment comprises a chemical transmission pipe, wherein an inner limiting thermal insulation layer is arranged on the outer side of the chemical transmission pipe, the inner side of the inner limiting thermal insulation layer is attached to the outer end of the chemical transmission pipe, an outer limiting thermal insulation layer is arranged on the outer side of the inner limiting thermal insulation layer, a heat preservation center core layer is arranged between the inner limiting thermal insulation layer and the outer limiting thermal insulationlayer, and the right end of the outer limiting thermal insulation layer is fixedly connected with a photothermal fastener. Compared with common chemical equipment heat preservation layers, deformationcan be generated according to difference changes between internal and external temperatures of the chemical equipment, the internal stress of the heat preservation layer structure can be balanced, internal stress deformation caused by temperature changes of the heat preservation layer structure is reduced, the situation that a heat preservation layer cannot be attached to a surface layer of the chemical equipment in the case of large internal and external temperature differences is reduced, the thermal insulation effect of the heat preservation layer structure on the chemical equipment is enhanced, and meanwhile internal cracks caused by stress are reduced.

The invention relates to the technical field of spiral blade forming machining, and particularly relates to a composite forming method for a thick spiral blade. The method comprises the following steps that a, blanking is carried out, and a plane body spiral blade blank blanking graph is calculated according to a spiral blade expansion calculation formula; b, a plane body spiral blade blank is heated, and the plane body spiral blade blank is converted into austenite at the high temperature; c, the plane body spiral blade blank is drawn, the first end of the edge of an inner hole notch of the high-temperature plane body spiral blade blank is fixed, the second end of the edge of the inner hole notch of the high-temperature plane body spiral blade blank is drawn through hoisting equipment, the inner spiral line of the spiral blade is stretched to the required size, and the plane body spiral blade blank is initially formed into a spiral blade; and d, the initially-formed spiral blade is placed on a prefabricated spiral mold, and pressure is applied to the prefabricated spiral mold through a press machine to press the prefabricated spiral mold into a standard thick spiral blade. According to the method, the inner diameter and the outer diameter of the formed spiral blade can be guaranteed, the method is suitable for mass production of thick spiral blades, the efficiency is high, andthe forming quality of the spiral blade is stable.