A high toughness and high tensile strength thick steel plate has a plate thickness of 100 mm or more, wherein a reduction of area in a center of the plate thickness by tension in a plate thickness direction is 40% or more. Thus, a high tensile strength thick steel plate with excellent strength and toughness in a center of the plate thickness can be obtained with no need for a larger production line, even in the case of producing a high strength thick steel plate for which the addition amount of alloying element needs to be increased.

A portion of a submerged combustion burner is disposed into a pressure vessel. The portion of the submerged combustion burner has a welded area that has a first microstructure defined by a first number of voids. The vessel is filled with an inert gas, pressurized, and heated. Pressurizing and heating operations are performed for a time and at a temperature and a pressure sufficient to produce a second microstructure in the welded area of the burner. The second microstructure is defined by a second number of voids less than the first number of voids.

Provided is a decompression heat-insulating pipe structure that can be used in the system operating at high temperatures. A decompression heat-insulating pipe structure of the present disclosure includes: an outer tube and an inner tube each having a flange; and a seal member between the flanges, the seal member being configured to keep a space between the outer tube and the inner tube in a decompression state, and a shifting means configured to shift the outer tube and the inner tube relatively so as to selectively dispose the tubes at a pressing position to press the seal member between the flanges and at a cancellation position to cancel the pressing of the seal member.

Method for forming a metallic component surface to achieve lower electrical contact resistance. The method comprises modifying a surface chemical composition and creating a micro-textured surface structure of the metallic component that includes small peaks and/or pits. The small peaks and pits have a round or irregular cross-sectional shape with a diameter between 10 nm and 10 microns, a height/depth between 10 nm and 10 microns, and a distribution density between 0.4 million/cm.sup.2 and 5 billion cm.sup.2.

A tool having a relatively ductile working end for engaging workpieces and a relatively hard non-working portion for driving the tool is disclosed, and a process for making same. The tool is formed with the material in a first state, such as by cold-working, and then only the non-working portion is heat treated to a second state. The working end is thus maintained in the ductile state while the non-working portion is hardened, thus imparting different materials performance characteristics to working end and non-working portion.

Embodiments herein relate to a heat sink having nano- and/or micro-replication directly embossed in a bulk solidifying amorphous alloy comprising a metal alloy, wherein the heat sink is configured to transfer heat out of the heat sink by natural convection by air or forced convection by air, or by fluid phase change of a fluid and/or liquid cooling by a liquid. Other embodiments relate apparatus having the heat sink. Yet other embodiments relate to methods of manufacturing the heat sink and apparatus having the heat sink.

The present invention provides a carburized part having a total amount of TiC, AlN and ZrC, which are precipitate particles, of 4.510.sup.10 mole or less per 1 mm.sup.2 of grain boundary area of prior austenite grains after carburization. According to the present invention, it is possible to provide a carburized part which allows effective inhibition of abnormal grain growth in spite of a carburizing treatment and makes it possible to solve the problem of reduction in properties caused by abnormal grain growth.

A Ni-based alloy consisting of, in terms of mass %: 0.10%<C?0.30%; Si?0.50%; Mn?0.50%; P?0.030%; S?0.010%; Cu?3.00%; 30.0%?Cr?39.0%; Mo?3.00%; Fe?3.00%; 2.00%?Al?5.00%; O?0.0100%; N?0.050%; Nb?0.50%; V?0.50%; Ti?0.50%; Ta?0.50%; W?0.50%; and at least one selected from the group consisting of 0.0010%?B?0.0100%, 0.0010%?Mg?0.0100%, and 0.0010%?Ca?0.0100%, with the balance being Ni and unavoidable impurities, in which the alloy comprises an austenite phase having an average grain diameter of 50.0 ?m or less, a M.sub.23C.sub.6-type carbide having an average circle equivalent particle diameter of 1.0 ?m or more, and a massive ?-Cr phase having an average circle equivalent particle diameter of 10.0 ?m or less.

The present invention discloses a method for manufacturing a screwdriver head, the screwdriver head including a head portion for being inserted into a slot of a screw head and a basal body for supporting the head portion; the manufacturing method including: providing the screwdriver head made of a first metal material; preparing alloying coating; coating the alloying coating on the surface of the head portion of the screwdriver head; conducting laser surface alloying treatment on the surface of the head portion coated with the alloying coating to form an alloyed layer; and conducting low temperature tempering treatment on the screwdriver head after the laser surface alloying treatment. The present invention further discloses a screwdriver head, the surface of the position at which the head portion of the screwdriver head contacts with the slot of the screw head is provided with an alloyed layer formed through the laser surface alloying treatment. The screwdriver head manufactured by the manufacturing method of the present invention has high rigidity and high abrasive resistance in the head portion and high tenacity in other portions, thereby prolonging the service life.

The present invention discloses a method for manufacturing a screwdriver head, the screwdriver head including a head portion for being inserted into a slot of a screw head and a basal body for supporting the head portion; the manufacturing method including: providing the screwdriver head made of a first metal material; preparing alloying coating; coating the alloying coating on the surface of the head portion of the screwdriver head; conducting laser surface alloying treatment on the surface of the head portion coated with the alloying coating to form an alloyed layer; and conducting low temperature tempering treatment on the screwdriver head after the laser surface alloying treatment. The present invention further discloses a screwdriver head, the surface of the position at which the head portion of the screwdriver head contacts with the slot of the screw head is provided with an alloyed layer formed through the laser surface alloying treatment. The screwdriver head manufactured by the manufacturing method of the present invention has high rigidity and high abrasive resistance in the head portion and high tenacity in other portions, thereby prolonging the service life.