46results about How to "Guaranteed fatigue performance" patented technology

The invention discloses a method for preparing a rubber asphalt mixture. The method comprises the following steps: adding tyre rubber powder into the road petroleum asphalt, and carrying out the stirring and reaction for 45 to 120 minutes to prepare the rubber asphalt; and adding N,N'-ethidence dioleamide into the heated stone material in the mineral aggregate, stirring the mineral aggregate evenly, then adding the rubber asphalt into the mineral aggregate, and stirring the mixture evenly to obtain the composite modified rubber asphalt mixture finished product. The obtained rubber asphalt mixture can simultaneously improve the high temperature performance and bonding performance of the rubber asphalt mixture.

The invention relates to a red mud-based asphalt mixture warm mix agent and a preparation method thereof, belonging to the technical field of asphalt warm mix agents. The method comprises: 1) calcining the red mud powder and mixing it with an active aluminum silicon source in proportion, and preparing SiO 2 / Al 2 o 3 mol ratio to obtain the geopolymer precursor; 2) the geopolymer precursor obtained in step 1) is added to the alkaline activator solution, and the geopolymer slurry is obtained after stirring; 3) the geopolymer slurry obtained in step 2) is Solidify the material slurry to obtain a geopolymer block, and then make the geopolymer block into powder; 4) add the geopolymer powder obtained in step 3) into the surfactant solution, stir the obtained slurry Suction filtration, drying, that is. The invention prepares the asphalt mixture warm mix agent by modifying the surface of the red mud base polymer powder, which effectively ensures the mechanical properties of the asphalt mixture while significantly reducing the mixing temperature and molding temperature of the asphalt mixture.

The invention discloses a micro injection mould for a biodegradable vascular stent and belongs to the technical field of polymer injection moulds. The micro injection mould for the biodegradable vascular stent is characterized by adopting a single-cavity injection mould with a split type mould cavity structure, four-time parting, multi-point sprue feeding and multiway sequential core pulling of an inclined sliding block, wherein the single-cavity injection mould comprises a mould frame part, a side parting part, a mould temperature control part and a vacuumizing part; and the micro injection mould for the biodegradable vascular stent mainly comprises a positioning ring, a sprue sleeve, a fixed mould fixed plate, a demoulding runner plate, a fixed template, a moveable template, a pad plate, a moveable mould fixed plate, a sliding block, a sliding block pressing plate, a limited steel ball, a wedge block, an inclined guide column, a mould core, a heating oil channel, a cooling water channel, a sealing ring, a limited rod, a spring, a guide column, a guide sleeve, a nylon sleeve fixed block and a nylon sleeve. The micro injection mould for the biodegradable vascular stent has the beneficial effects of forming the vascular stent at one step, guaranteeing the size precision, the surface quality, the integral strength and the fatigue performance required by the stent, realizing automatic production, improving the production efficiency and reducing the manufacturing cost of the vascular stent.

The invention relates to an evaluation method for fatigue performance of a steel pipe welding intersecting joint. The area of the contact face of a welding line in the steel pipe welding intersecting joint and a main pipe and the area of the contact face of the welding line in the steel pipe welding intersecting joint and a branch pipe are adopted as evaluation indexes of the fatigue performance of the steel pipe welding intersecting joint; and the area of the contact face of the welding line in the steel pipe welding intersecting joint and the main pipe and the area of the contact face of the welding line in the steel pipe welding intersecting joint and the branch pipe are calculated and compared, and the small value is taken for evaluating the fatigue performance of the steel pipe welding intersecting joint. According to the evaluation method, all current evaluation indexes for the fatigue performance of the steel pipe welding intersecting joint can be comprehensively taken into consideration, and the fatigue performance of the steel pipe welding intersecting joint is evaluated more reasonably.

The invention discloses a process for controlling the microstructure of a rail flash welding joint of R350HT rail with an extremely upper limit Mn content, belonging to the technical field of rail flash welding. In order to solve the technical problem in the prior art that the flash-welded joint of the R350HT rail is easily caused to appear martensite, the invention provides a process for controlling the microstructure of the flash-welded joint of the R350HT rail with the upper limit Mn content, including the welding process and the post-weld treatment; In the welding process, the welding heat input is controlled to be 8.5-9.5MJ for pulsation or preheating flash welding, and the welding upsetting amount is 15.5-16.0mm; in the post-weld treatment, the joint is naturally cooled to 575-585 ℃, and then cooled to ≤250℃, and finally cooled to room temperature naturally. Through the comprehensive control of the chemical composition of the rail, the hot rolling process, the welding process, and the cooling after welding, it is ensured that there is no abnormal structure such as martensite in the rail flash welded joint, and the mechanical properties of the joint are also guaranteed.

The invention discloses a technique for controlling the upper limit Mn content of R350HT rail flash welding joint structure, and belongs to the technical field of rail flash welding. In order to solve the technical problem in the prior art that easily leads to martensitic structure in the R350HT rail flash welding joint, the present invention provides a process for controlling the upper limit Mn content of the R350HT rail flash welding joint structure, including welding process and post-weld treatment; welding In the process, the welding heat input is controlled to be 8.0-9.0MJ pulsation or preheating flash welding, and the welding upsetting amount is 15.0-15.8mm; in the post-welding treatment, the joint is naturally cooled to 550-580°C, and then heat-preserved and cooled to ≤ 250°C, and finally cooled to room temperature naturally. Through the comprehensive control of the chemical composition of the rail, hot rolling process, welding process, and post-weld cooling, it is ensured that there is no abnormal structure such as martensite in the rail flash welded joint, and at the same time, the mechanical properties of the joint are guaranteed.

The invention discloses a technique for controlling the joint structure of flash welding joints of R350HT rail with lower limit Mn content, and belongs to the technical field of rail flash welding. In order to solve the technical problem in the prior art that easily leads to martensitic structure in the flash welded joint of R350HT rail, the present invention provides a process for controlling the microstructure of the flash welded joint of R350HT rail with a lower limit of Mn content, including welding process and post-weld treatment; In the welding process, the welding heat input is controlled to be 3.5-4.5MJ pulsation or preheating flash welding, and the welding upsetting amount is 10.0-11.5mm; in the post-welding treatment, the joint is naturally cooled to room temperature in the air. Through the comprehensive control of the chemical composition of the rail, hot rolling process, welding process, and post-weld cooling, it is ensured that there is no abnormal structure such as martensite in the rail flash welded joint, and at the same time, the mechanical properties of the joint are guaranteed.

The invention discloses a technology for controlling the flash welding joint structure of R350HT rail with upper and lower Mn content, and belongs to the technical field of rail flash welding. In order to solve the technical problem in the prior art that easily leads to the martensite structure of the R350HT rail flash welding joint, the present invention provides a process for controlling the upper limit Mn content of the R350HT rail flash welding joint structure, including the welding process and post-weld treatment; In the welding process, the welding heat input is controlled to be 7.0-8.5MJ pulsation or preheating flash welding, and the welding upsetting amount is 14.5-15.5mm; in the post-welding treatment, the joint is naturally cooled to 525-560°C, and then heat-preserved and cooled to ≤250°C, and finally cool down to room temperature naturally. Through the comprehensive control of the chemical composition of the rail, hot rolling process, welding process, and post-weld cooling, it is ensured that there is no abnormal structure such as martensite in the rail flash welded joint, and at the same time, the mechanical properties of the joint are guaranteed.

The invention discloses a ductile composite bridge deck composed of cold-formed Z-shaped steel, which comprises cold-formed and curled Z-shaped steel, transverse steel bars and ultra-high toughness concrete. The cold-formed Z-shaped steel is continuously placed laterally along the bridge deck and welded by fillet welds to form the steel skeleton of the bridge deck. The lower flange of the cold-formed Z-shaped steel is longer, which plays the role of external reinforcement of the plate surface; the upper flange is shorter and has a row of round holes on it, and the transverse steel bars pass through each cold-formed Z-shaped steel flange through the round holes. The ultra-high toughness concrete is poured on the steel skeleton of the bridge deck to protect the steel skeleton of the bridge deck. In the composite bridge deck system proposed by the present invention, the ultra-high toughness concrete can ensure that no or only tiny cracks below 100 microns will be generated, and the toughness and durability of the structure will be improved; The anti-shear and pull-out effects of the studs are improved, and the out-of-plane stability of the bridge deck is improved, the material cost and construction complexity are significantly reduced, and the fatigue performance is superior.