Abstract:
The grain-oriented electrical steel sheet is a grain-oriented electrical steel sheet which does not have an inorganic coating containing forsterite as a main component, including a base steel sheet having a predetermined chemical component, a silicon-containing oxide layer provided on the base steel sheet, an iron-based oxide layer provided on the silicon-containing oxide layer, and a tension-insulation coating provided on the iron-based oxide layer, having a thickness of 1 to 3 μm, and containing phosphate and colloidal silica as main components. When elemental analysis is performed from a surface of the tension-insulation coating in a sheet thickness direction by glow discharge optical emission spectrometry, predetermined requirements are satisfied.
Abstract:
A method for treating and phosphatizing a metal board without using acid includes the following steps: performing a degreasing step to remove grease and dirt from a surface of the metal board with a degreasing agent; performing a blast-peening step by blasting and peening polygon blast-peening granules on the metal board through a centrifugal impeller to remove an oxidized layer; performing a washing step to clean remaining powders from the metal board after the blast-peening step; performing a phosphatizing step to form a protective phosphate coating on the metal board; performing another washing step to wash off remaining phosphatizing agents from the metal board; performing a rustproofing step to apply a rustproofing agent on the metal board; and performing a drying step to dry the metal board.
Abstract:
An objective of the present invention is to provide a threaded connection for pipe or tube having an excellent anti-misalignment property and an appropriate shouldering torque, and further having excellent corrosion resistance and an excellent adhesiveness of a solid lubricant coating, and to provide a method of producing the threaded connection for pipe or tube. The threaded connection for pipe or tube according to the present embodiment includes a pin and a box. The pin and the box have contact surfaces including thread portions and unthreaded metal contact portions. The threaded connection for pipe or tube comprises an alloy plating layer consisting of a Zn—Ni alloy on the contact surface of at least one of the pin and the box, a phosphating layer, and a solid lubricant coating. These are stacked in an order of the alloy plating layer, phosphating layer, and the solid lubricant coating, from a contact surface side.
Abstract:
Provided is a treatment solution for chromium-free tension coating that can simultaneously achieve excellent moisture absorption resistance and a high iron loss reduction effect obtained by imparting sufficient tension, by using an inexpensive Ti source instead of expensive Ti chelate. The treatment solution for chromium-free tension coating contains: one or more of phosphates of Mg, Ca, Ba, Sr, Zn, Al, and Mn; colloidal silica in an amount of 50 parts by mass to 120 parts by mass per 100 parts by mass of the phosphate in terms of solid content of Ti source in an amount of 30 parts by mass to 50 parts by mass per 100 parts by mass of the phosphate in terms of solid content of TiO2; and H3PO4, and the number of moles of metallic elements in the phosphate and of phosphorus in the treatment solution satisfy: 0.20≦[Mg]+[Ca+[Ba]+Sr]+[Zn]+[Mn]+1.5[Al])/[P]≦0.45 (1).
Abstract:
The invention relates to a method and coating agents used in the method which provide good adherence to and good corrosion protection of metal substrates; the coating coating agents are cross-linkable via radical polymerization. Adhesion promoting compounds are present in the conversion layer in a quantity of about 0.01 to 40 weight percent and contain, on average, one reactive unsaturated group and at least one H-active group per molecule.
Abstract:
An object of the present invention is to provide galling resistance to a threaded joint used for an oil well pipe. On a thread portion and a metallic sealing portion of the joint, there is provided a manganese phosphate chemical formation coating layer, or alternatively there are provided a nitriding layer of 1 to 20 .mu.m thickness and a manganese phosphate chemical formation coating layer of 5 to 30 .mu.m thickness, and also there is coated a solid lubricant which contains powder of molybdenum disulfide or tungsten disulfide and also contains one of epoxy resin, furan resin and polyamide resin as an essential component, and a ratio of composition is maintained at a specific value, so that a solid lubricant coating layer of 10 to 45 .mu.m thickness can be formed by heating.Due to the above surface treatment, even when the frequency of repetition of fastening and unfastening of the joint is increased, the occurrence of galling can be prevented over a long period of time.
Abstract:
A process for phosphating surfaces of steel, galvanized or alloy-galvanized steel, aluminum, aluminized or alloy-aluminized steel. The process is particularly useful for treating metal surfaces which are to be cathodic electrocoated. The process uses a nickel, cobalt, copper, nitrite and oxo-anion of halogen free phosphating solution containing 0.3 to 2.0 g/l Zn(II), 0.3 to 4 g/l Mn(II), 5 to 40 g/l phosphate ions and at least one of 0.5 to 5 g/l hydroxylamine and 0.2 to 2 g/l m-nitrobenzene sulfonate wherein the ratio by weight of Zn(II) to Mn(II) is not greater than 2.
Abstract:
A solution which is stored in a treatment bath is stirred by vibration stirring means provided in the treatment bath in a range of receiving a metal molded article or around a substantially horizontal surface of the metal molded article so that mean acceleration a expressed in the following equation is at least 8 cm/sec.sup.2 : ##EQU1## where X, Y and Z, which are in units of cm/sec.sup.2, represent average acceleration values of flow rate changes within 60 seconds, measured simultaneously in three axial directions of X, Y and Z which are perpendicular to each other at a measuring position.
Abstract:
The present invention produces a highly corrosion-resistant, highly rust-inhibiting, and strongly paint-adherent conversion coating on the surface of magnesium-containing metals, and does so rapidly and at relatively low temperatures, using a substantially chromium-free conversion treatment bath.
Abstract:
An aqueous solution of manganese phosphate and phosphoric acid, preferably with little or no content of any material conventionally recognized as an accelerator or of any divalent metal ions other than manganese and iron, forms a good quality paint undercoating phosphate conversion coating on metal substrates, particularly on steel and galvanized steel substrates, when contacted by spraying or immersion with the substrates at a temperature of 54.degree.-65.degree. C. for a time of 2-5 minutes.