35results about How to "Improve thermal crack resistance" patented technology

The invention discloses a sulfuric acid corrosion-resistant pure austenitic stainless steel electrode with high nickel and copper content and low thermal crack sensitivity, which is composed of a nickel-chromium-molybdenum-copper-iron alloy welding core and a coating covering the surface of the welding core. The content is: 7-13 parts by weight of rutile powder, 4-8 parts by weight of marble powder, 1.0-4.0 parts by weight of fluorite powder, 1.5-4.0 parts by weight of mica powder, 1.5-3.0 parts by weight of potassium feldspar powder, 2-3 parts by weight of electrolytic manganese parts by weight, 0.25-0.6 parts by weight of niobium powder, 1.0-2.0 parts by weight of metallic chromium powder, 0.2-0.6 parts by weight of ferromolybdenum powder, 0.1-0.5 parts by weight of soda ash and 0.1-0.5 parts by weight of sodium alginate. Compared with the existing ones, the electrode deposited metal of the invention has excellent mechanical properties, strong thermal crack resistance and excellent intergranular corrosion resistance.

The invention discloses a bainitic steel wheel for rail transit produced at low cost and fine-tuned, and a manufacturing method thereof. , rare earth RE: 0.001~0.040%, phosphorus P≤0.020%, sulfur S≤0.020%, the rest is iron and unavoidable residual elements; and 3.00%≤Si+Mn≤5.00%. Compared with the existing technology, through the alloy design and manufacturing process, especially the heat treatment process and technology, the wheel rim obtains a carbide-free bainite structure; the spoke plate and the hub obtain a granular bainite and supersaturated ferrite structure And a small amount of pearlite, the wheel has high comprehensive mechanical properties; no special alloying elements such as Mo, Ni, V, Cr and B are added, and the heat treatment process and technology are fully utilized to greatly reduce the cost of steel and realize precise production.

A flux-cored welding wire for submerged arc welding, including a steel strip and a flux core, wherein the chemical composition of the steel strip, by weight percentage: C≤0.02%, Mn0.2‑1.2%, Si0.3‑1.8%, Cr22‑28 %, W2‑8%, Cu 0.2‑0.4%, V0.1‑0.3%, S≤0.005%, P≤0.006%, the balance is Fe; the composition of the drug core is calculated by its weight percentage: marble 20‑35%, Fluorite 15‑28%, Mica 7‑12%, Titanium Dioxide 6‑14%, Ferro Vanadium 2‑8%, Ferrosilicon 2‑6%, FerroTitanium 2‑12%, Ferroboron 13‑17%, Ferromolybdenum 2-8%, graphite 3-12%, and the balance is ferrochromium; the welding wire of the present invention can improve its toughness and crack resistance while improving the hardness of the deposited metal, and improve it from both metallurgy and technology. It ensures the strength, toughness and crack resistance of high-hardness deposited metal, and at the same time ensures good welding processability, easy slag removal, no spatter, high hardness and excellent wear resistance.

The invention discloses a centrifugal metal roll ring and a manufacturing process thereof. The centrifugal metal roll ring comprises an inner layer and an outer layer which are made of different materials. The inner layer comprises 0.80%-1.2% of C, 1.00%-2.00% of Si, 0.50%-1.50% of Mn, not larger than 0.03 of P, 0.20%-1.00% of Ni, not larger than 0.20% of Mo, not smaller than 0.04% of Mg and the balance Fe. The outer layer comprises 2.00%-3.00% of C, 0.50%-1.50% of Si, 0.80%-1.50% of Mn, not larger than 0.10% of P, not larger than 0.03% of S, 12.00%-18.00% of Cr, not smaller than 0.50% of Ni, 0.20%-1.50% of Mo and the balance Fe. Compared with high-chromium cast iron and a high-carbon semi-steel roll ring which are obtained through inblock casting and centrifugal casting, by the adoption of the centrifugal metal roll ring, precious metal is saved, production cost is lowered by 18% to 22%, the roll ring is easy to cut, and the matrix organization, impact toughness, wear resistance and heat crack resistance can be improved greatly.

The invention provides a low-cost, high-wear-resistant stretch-reducing roll and its heat treatment process. The normal-temperature hardness of the low-cost, high-wear-resistant stretch-reducing roll obtained by the invention is >50HRC, and the tensile strength is >700MPa. It overcomes the problems of high roll consumption of the stretching and reducing roll, easy breakage of the roll when the diameter is large, and ring-shaped rolling marks on the roll surface during the rolling process.

The invention discloses a low-zinc hot dipping aluminum alloy coating material containing Mg multiple combination metamorphism. The material comprises, by weight, 20% to 22% of alloying component Zn, 4.0% of alloying enhancer Cu, 0.2% of polarization metamorphism agent Mg, 1% of solvent passivant Mn, 0.1% of precipitation hardening agent Sb, 0.01% of grain refiner Zr, 2.0% of substrate interface reaction buffer agent Fe, 0.5% of rare earth addition, the balance A1 and inevitable trace impurities. The problem that hot-dip galvanizing occupies a high proportion of zinc is solved, zinc resources are saved, the aluminum alloy coating materials which are good in wettability to base steel, high in bonding force, high in intensity, good in extensibility, high temperature resistance, good in corrosion resistance, good in machinability and weldability are obtained by utilizing Mg and the above alterant and low-zinc aluminum alloys, and the aluminum alloy coating materials are used for hot dipping of high quality steel.

The invention discloses low zinc hot dipping aluminium alloy plating material containing Ca multi-combination metamorphism. The composition of alloy comprises, by element weight, 10%-13% of Zn, 5.0% of alloy enhancer Cu, 0.03 % of polarization metamorphic agent Ca, 0.2 % of solvent passivator Mo and 0.5% of rare earth addition, and the rest of the composition of the alloy are A1 and micro impurities which are unavoidable. The low zinc hot dipping aluminium alloy plating material containing the Ca multi-combination metamorphism solves the problems that due to dissolution of iron in a hot dipping plating process, zinc liquid viscosity is enabled to be increased and the capability of the surface of an infiltrating steel matrix is reduced, the thickness of a zinc layer is obviously increased due to the fact that iron content in zinc liquid is increased, and therefore ductility and the appearance of the a plating layer are enabled to be poor, and other problems are solved too. The aluminium alloy plating material for hot dipping is obtained, wherein the aluminium alloy plating material for hot dipping is good in matrix wettability, strong in binding force, high in strength, good in extensibility, high temperature-resistance, thin in plating layer, and strong in corrosion resistance.

The invention relates to heat-resisting spheroidal graphite cast iron and a preparation method thereof. The preparation method comprises the following steps: smelting alloy, wherein the alloy comprises the following ingredients by mass: 2.7-3.5% of C, 4.0-5.0% of Si, 1.5-3.5% of W, 0.02-0.05% of Mg, 0.1-0.5% of V, Re being less than 0.03%, 0.15-0.6% of Mo, 0.05-1.0% of Mn, 0 to 0.03% of P, 0 to 0.02% of S, and the balance of iron and unavoidable impurities, discharging molten iron, inoculating the molten iron, spheroidizing, and casting. The heat-resisting spheroidal graphite cast iron prepared by the preparation method is of excellent high-temperature oxidation resistance, high-temperature anti-cracking property and thermal fatigue performance, and is good in mechanical property, low in production cost, and suitable for producing parts of an engine emission system.

The invention discloses a roller producing technology for a high-end rail rolling mill. The roller producing technology comprises the following steps that firstly, an appropriate number of nickel elements and molybdenum alloy elements and a trace of yttrium basis weight heavy rare earth elements, vanadium elements, niobium elements and boron elements are added, and high-purity molten iron is smelted; secondly, calcium silicon and rare earth magnesium balling is carried out, and continuous generating is carried out through a barium calcium nucleating agent; thirdly, still standing is carried out for a moment after generating, roller pouring is carried out, heat preservation is carried out after pouring till the temperature is equal to the normal temperature, a box is opened, and a roller workblank is obtained; fourthly, a hole is formed in the roller workblank in a coarse mode, a 30-50 mm machining margin is reserved on the single edge in the diameter direction, the roller wokblank is placed in a boiler to be processed at the high temperature, the temperature rises to A cm+30 DEG C, and heat preservation is carried out for a period of time; fifthly, the roller workblank is taken out of the boiler to be hung to a large spray quenching machine to rotate, thermal refining is carried out through water mist spray quenching, and after the temperature of the roller workblank is lowered to the range from 380 DEG C to 450 DEG C, the roller workblank is placed back to the boiler, and heat preservation is achieved. A roller produced through the technology is high in strength and good in abrasion-resisting performance, and almost no hardness difference exits between the roller surface and the bottom of a hole groove or between the roller surface and the side walls or between the roller surface and other areas.