34results about How to "Reduce residual stress levels" patented technology

The invention relates to a straightening and leveling process for hot-rolled high-strength steel. The straightening and leveling process is characterized in that: hot-rolled high-strength band steel is fed into a straitening machine and a leveling machine in sequence. The process comprises the following specific steps of: firstly, setting the total elongation rate of a unit according to yield strength needed by a band steel product on the tail of a process section; secondly, distributing a total elongation rate set value to the straitening machine and the leveling machine for presetting the straightening and leveling process; thirdly, detecting the total elongation of detected and processed band steel in real time; and lastly, comparing the total elongation of the detected and processed band steel with the total elongation rate set value, dynamically adjusting the rolling force of the leveling machine in real time to ensure that the total elongation rate of a band steel product on the tail of the process section is constant, lowering the residual stress level of the band steel by using the straightening machine, and ensuring the performance quality of the band steel product on the tail of the process section. Due to the adoption of the process, the internal residual stress level of the hot-rolled band steel can be lowered fully, and the performance quality of a hot-rolled high-strength steel product is improved effectively.

The invention belongs to the field of laser additive manufacturing repair, and particularly relates to alloy powder for repairing martensitic steel through laser additive manufacturing and preparationand application of the alloy powder. The alloy powder contains the following components of, in percentage by mass, 0.03%-0.4% of C, 6%-10% of Cr, 4%-8% of Ni, 0.5%-1.5% of Mn, 0.6%-1.2% of Si and thebalance Fe and inevitable impurities, so that the alloy powder has a relatively low martensite phase transformation point. The alloy powder is used for repairing the martensitic steel through laser additive manufacturing, a martensitic structure is formed in a repaired area, the volume expansion effect of martensitic phase transformation is used for counteracting heat shrinkage generated by cooling of the repaired area, residual compressive stress is generated in the repaired area, the defects of deformation, fatigue cracks and the like of repaired parts are avoided, timeliness and reliability of part repairing are improved, and the damaged part can be used immediately after being repaired.

The present invention relates to a method of manufacturing thick gauge aluminum alloy plates with low residual stress levels, said method comprising: (a) providing a solution heat treated and quenched aluminum alloy plate having a thickness of at least 80 mm; (b) by adding said Cold rolling of the plate stress relieves it, resulting in a reduction of up to 8% in the thickness direction of the plate product.

The invention relates to a method for molding a high-strength high-modulus aluminum base composite material. The process comprises the following steps: firstly, performing solution treatment and quenching on an aluminum base composite material board at a temperature of between 450 and 550 DEG C; placing the aluminum base composite material board on a mold and sealing the joint part of the aluminum base composite material board and the mold; vacuumizing a molding surface cavity of the aluminum base composite material board and the mold until the pressure is between 1 x 10<-7> and 1 x 10<-12> MPa; placing the board and the mold into an autoclave and generating the pressure of between 150 and 500 MPa to act on the surface of the aluminum base composite material board; then raising the temperature to between 20 and 300 DEG C and aging for 5 to 50 hours; and after the aging, reducing the temperature to between 15 and 50 DEG C, and unloading the pressure to normal pressure; and generating rebounding on the components due to the residual elastic deformation and restoration to obtain parts of corresponding shapes. The method can greatly reduce the probability of the occurrence of processing cracks of the aluminum base composite material, improve microstructures, improve the material strength, and is suitable for the precise molding of frame rib web plate and wall-board parts which are made of the high-strength high-modulus aluminum base composite material and have large plane size, complex molding surface structure and high accuracy.

The invention provides best strain of an austenitic stainless steel container welding residual stress overload reducing method. The best strain of the austenitic stainless steel container welding residual stress overload reducing method comprises: (1) a best value exists in overload dependent variable for reducing welding residual stress, the dependent variable corresponding to first major principal stress in direction in a continuous structure zone serves as an evaluation index and overload plastic strain is in a range of 2%-5%; (2) in the process of overload, boosting speed is controlled through a variable frequency pump or an automatic control reflux valve, uploading speed is in a range of 0.2 MPa/min-0.4 MPa/min and the dependent variable is controlled through deformation measurement or strain measurement; and (3) when a container is manufactured, a tensile test is firstly performed to materials, design stress and overload stress are determined according to an actual single tensile curve of the materials and design pressure and overload pressure are calculated through a simplified method. Numerical modeling has universality and generality, evaluation stress is corroded, first tensile welding residual stress is reduced to a great extent and the residual stress after reduction is in the same level with residual stress of a cold rolling plate rear base material and residual stress after stress relief heat treatment.

The invention is suitable for the technical field of vacuum coating, and provides a bionic-structure cubic boron nitride coating and a preparation method thereof. The bionic-structure cubic boron nitride coating is coated on a substrate, and consists of a bottom ductile layer and a top high-hardness layer, wherein the high-hardness layer is a cubic boron nitride layer; the ductile layer is in a multi-layer composite structure formed by alternate deposition of M2 layers and M1Bx:M2 doped composite layers; each M1Bx:M2 doped composite layer is formed by doping of M1Bx in M2; the M1 and the M2 are the same or different transition metal; and x is equal to or lager than 0.5 and equal to or smaller than 4.

The invention discloses a CrCuV solid solution for heterogeneous interface bonding and a preparation method and application thereof. The CrCuV solid solution comprises the following components in percentage by weight: 33-42% of copper; 25-35% of vanadium; and the balance of chromium. A gradient material with the CrCuV solid solution as the transition layer is synthesized from the CrCuV solid solution by using a laser additive manufacturing or fusion welding means. The difference in thermal expansion coefficient, melting point, elastic modulus, etc. of the heterogeneous interface is effectivelyalleviated, the residual stress level at the heterogeneous interface during the additive manufacturing process can be reduced, the precipitation of hard and brittle phases is avoided, the manufacturing requirements of heterogeneous parts can be reached, and a high-strength bonding interface is created. The CrCuV solid solution used for the connection of heterogeneous materials can have high connection interface strength and hardness, and can be widely used in the bonding of heterogeneous parts such as steel-aluminum, steel-tungsten, or steel-copper.

The invention provides high-toughness wear-resistant steel with excellent cold bending performance and a manufacturing method thereof. The steel comprises the following components in percentage by weight: 0.30%-0.38% of C, 0.10%-0.25% of Si, 0.80%-1.60% of Mn, less than or equal to 0.010% of P, less than or equal to 0.003% of S, 0.2%-0.4% of Mo, 4.5%-5.5% of Ni, 0.7%-1.5% of Cr, 0.45%-0.55% of Ti, 0.015%-0.045% of Als, less than or equal to 0.0060% of N, less than or equal to 0.0020% of H and the balance of iron and inevitable impurities. The manufacturing method comprises the steps of molten iron pretreatment, converter smelting, external refining, die casting or continuous casting, heating, rolling and heat treatment. According to the steel plate produced through the method, the yield strength reaches 967-1048 MPa, the tensile strength reaches 1248-1359 MPa, the surface hardness reaches 420-468 HBW, the core hardness reaches 417-467 HBW, the ballistic work at the temperature of-40 DEG C is larger than or equal to 44 J, and 90-degree cold bending d = 5a is qualified.