3426 results about "Austenitic stainless steel" patented technology

The present invention provides an austenitic stainless steel tube with a uniform fine grained structure of regular grains, which is not changed to a coarse structure and the steam oxidation resistance is maintained even if the tube is subjected to a high temperature reheating during welding and high temperature bending working. The austenitic stainless steel tube consists of, by mass %, C: 0.03–0.12%, Si: 0.1–0.9%, Mn: 0.1–2%, Cr: 15–22%, Ni: 8–15%, Ti: 0.002–0.05%, Nb: 0.3–1.5%, sol. Al: 0.0005–0.03%, N: 0.005–0.2% and O (oxygen): 0.001–0.008%, and the balance Fe and impurities, the austenitic stainless steel tube having austenitic grain size number of 7 or more and a mixed grain ratio of preferably 10% or less.

Disclosed is an austenitic stainless steel which comprises the following components: C: 0.04-0.18%, Si: 1.5% or less, Mn: 2.0% or less, Ni: 6-30%, Cr: 15-30%, N: 0.03-0.35%, and sol.Al: 0.03% or less, and which further comprises at least one component selected from 1.0% or less of Nb, 0.5% or less of V and 0.5% or less of Ti, with the remainder being Fe and impurities, wherein the impurities contain the following components: P: 0.04% or less, S: 0.03% or less, Sn: 0.1% or less, As: 0.01% or less, Zn: 0.01% or less, Pb: 0.01% or less and Sb: 0.01% or less, and wherein the following formulae are fulfilled: P1 = S+[(P+Sn) / 2]+[(As+Zn+Pb+Sb) / 5] = 0.06; and 0.2 = Nb+2(V+Ti) = 1.7-10xP1. The austenitic stainless steel has high strength and, when used in a welded part, can exhibit excellent embrittlement crack resistance during being used at a high temperature. The steel is suitable as a material for an instrument that is intended to be used at a high temperature for a long period, such as a boiler for power generation.

The invention provides a nitrogenous nickel-free stainless steel and a powder-metallurgical molding technology, relating to the field of stainless steel production. Nitrogenous stainless steel powder and a prepared cementing agent are mixed evenly in a mixing machine and then crashed to injection molding feedstock; injection molding blanks with smooth surfaces and without macro defects are obtained by an injection molder under appropriate injection temperature and injection pressure; after degreasing by chlorylene solvent, thermal degreasing and presintering are carried out to the injection molding blanks, thermal degreasing blanks with certain strength and without defects are obtained; the thermal degreasing blanks are sintered and densified in nitrogen based atmosphere, therefore, products with higher density and more excellent performance can be obtained. The nitrogenous nickel-free stainless steel of the invention can solve the problems that resource price of the nickel-contained stainless steel is expensive and the contained nickel thereof is harmful to human health and the like, extends the application scope of nitrogenous austenitic stainless steel. The materials prepared by using the nitrogenous nickel-free stainless steel of the invention are better than traditionally smelted austenitic stainless steel in terms of performance and the nitrogenous nickel-free stainless steel of the invention is resource saving and environmentally friendly.

The invention relates to a welding wire, in particular to a welding wire applying to austenitic submerged arc welding for low-temperature equipments, in terms of chemical composition and weight percent, comprising Cr: 19.0 to 23.0%, Ni: 9.0 to 12.0%, C: <=0.03%, Mn: 1.60 to 2.50%, Si: 0.30 to 0.60%, Mo: <=0.30%, Cu: <=0.30%, Co: <=0.20%, Ti: <=0.015%, Nb: <=0.05%, V: <=0.10%, B: <=0.005% and Fe as allowance. The welding wire has the advantages that: the welding wire steelmaking craft is stable; the drawing performance is good; the invention meets the welding technical requirements of the high-intensity, high-toughness and anti-corrosion steel with low temperature and low temperature equipments; the invention can apply to the steel of 500 to 750MPa strength level; the invention is suitable for large range of welding current and no blowhole; the moulding is beautiful; the weld joint can be well matched with the base material.

The production method of austenitic stainless steel plate fin heat exchanger includes the following steps: part preparation: partition, sealing strip, fin, sealing head and connecting pipe preparation; cleaning before welding; acid pickling to remove oil, dirt and oxide, and using high-pressure water to wash; element assembling and holding; vacuum braze welding, adopting argon arc welding to weldscaling head and connecting pipe, making general assembly; test and inspection, making x-ray inspection, helium leak detection, flow resistance test, pressure test, TUV, ASME and other test and inspection. Said invented process raise the production quality of said stainless steel plate fin heat exchanger, tensile-strength of connector and its service life.

An austenitic-ferritic stainless steel having a low Ni content and a high N content is provided. A stainless steel which contains, in mass %, 0.2 % or less of C, 4 % or less of Si, 12 % or less of Mn, 0.1 % or less of P, 0.03 % or less of S, 15 to 35 % of Cr, 3 % or less of Ni, and 0.05 to 0.6 % of N, and is mainly composed of an austenite phase and a ferrite phase, wherein the proportion of said austenite phase is 10 to 85 volume %. The above austenitic-ferritic stainless steel exhibits good formability and high punch stretch formability, and is excellent in the resistance to crevice corrosion, to the corrosion of a welded zone and to intergranular corrosion. The above austenitic-ferritic stainless steel wherein the austenite phase contains C and N in a total amount of 0.16 to 2 mass % exhibits further improved formability.

An austenitic stainless steel with minimized deformation by heating and cooling treatment after cold working, which consists of, % by mass, C: 0.03% or less, Si: 2 to 4%, Mn: 0.1 to 2%, P: 0.03% or less, S: 0.03% or less, Ni: 9 to 15%, Cr: 15 to 20%, N: 0.02 to 0.2%, Nb: 0.03% or less, each of Mo and Cu or a total of Mo and Cu: 0.2 to 4%, and the balance Fe and impurities, and satisfies the following formulas (1) and (2). This steel can also have good weldability when the following formula (3) is also satisfied in addition to the formulas (1) and (2);16.9+6.9Ni+12.5Cu−1.3Cr+3.2Mn+9.3Mo−205C−38.5N−6.5Si−120Nb≧40  (1)450−440(C+N)−12.2Si−9.5Mn−13.5Cr−20(Cu+Ni)−18.5Mo≦−90  (2)8.2+30(C+N)+0.5Mn+Ni−1.1(1.5Si+Cr+Mo)+2.5Nb≦−0.8  (3)wherein each element symbol in the formulas (1), (2) and (3) represents the content, % by mass, of each element included in the steel.

An austenitic stainless steel excellent in high temperature strength, high temperature ductility and hot workability, consisting of, by mass %, C: more than 0.05% to 0.15%, Si: 2% or less, Mn: 0.1 to 3%, P: 0.04% or less, S: 0.01% or less, Cr: more than 20% to less than 28%, Ni: more than 15% to 55%, Cu: more than 2% to 6%, Nb: 0.1 to 0.8%, V: 0.02 to 1.5%, sol. Al: 0.001 to 0.1%, but sol.Al<=0.4xN, N: more than 0.05% to 0.3% and O (Oxygen): 0.006% or less, but O<=1 / (60xCu), and the balance Fe and impurities. The austenitic stainless steel may contain at least one of Co, Mo, W, Ti, B, Zr, Hf, Ta, Re, Ir, Pd, Pt and Ag, and / or at least one of Mg, Ca, Y, La, Ce, Nd and Sc.

The invention discloses a flux-cored wire for austenitic stainless steel welding. The flux-cored wire consists of a flux core and an external steel belt; the external steel belt is an austenitic stainless steel belt of which the carbon content is less than 0.025 percent; the carbon content of the flux core is not greater than 0.04 percent and carbon accounts for 18.0 to 24.0 percent based on the total weight of the flux-cored wire; the flux core comprises the following components in percentage by weight: 18.5 to 25.0 percent of metal chromium powder, 8.0 to 10.0 percent of metal nickel powder, 2.0 to 5.0 percent of electrolytic manganese metal, 1.0 to 3.0 percent of aluminum magnesium alloy, 28.0 to 35.0 percent of rutile, 3.0 to 5.0 percent of quartz, 2.0 to 5.0 percent of zircon sand, 2.0 to 5.0 percent of feldspar, 1.0 to 2.0 percent of cryolite, 2.0 to 5.0 percent of arc stabilizer and the balance of iron powder; and the arc stabilizer consists of K2O, Na2O and TiO2 in a weight ratio of (6.0-8.0):(8.0-10.0):(68.0-70.0), and the water content is not greater than 400 ppm.

A dental magnetic attachment which has a superior magnetic attractive force with a small nonmagnetic welded part and a flat welded surface to be polished. The dental magnetic attachment including a magnet, a yoke with a pit to hold the magnet, a sealing disk placed on the opening of the pit to cover the magnet and a nonmagnetic welded part between the yoke and the disk. The yoke and the disk are made from soft magnetic material. The nonmagnetic welded part, which joins the yoke and the disk, is formed by welding the yoke, the sealing disk, the sealing ring made from nonmagnetic austenitic stainless steel and a Ni coat between the sealing disk and the sealing ring together. Here, it is preferably that there remains a part of the nonmagnetic sealing ring. The welded surface of the dental magnetic attachment is polished to be flat.

A superpure high-nitrogen stainless austenite steel contains Cr (17-19 wt.%), Mn (12-16 wt.%), Mo (2-3 wt.%), Cu (0.5-1.5 wt.%), Ni (0-0.2 wt.%), N (0.4-0.6 wt.%), C (0-0.05 wt.%), Si (0-0.5 wt.%), S (0-0.009 wt.%), P (0-0.009 wt.%) and Fe (rest). It is smelted by vacuum induction furnace, where nitrogen is added in FeCrN, CrN or MnN mode.