摘要:
A spring steel wire includes, by mass %, C: 0.40% to 0.75%, Si: 1.00% to 5.00%, Mn: 0.20% to 2.00%, P: 0.0001% to 0.0500%, S: 0.0001% to 0.0500%, Cr: 0.50% to 3.50%, Al: 0.0005% to 0.0500%, N: 0.0020% to 0.0100%, Mo: 0% to 2.00%, V: 0% to 0.50%, W: 0% to 0.50%, Nb: 0% to 0.100%, Ti: 0% to 0.100%, Ca: 0% to 0.0100%, Mg: 0% to 0.0100%, Zr: 0% to 0.1000%. B: 0% to 0.0100%, Cu: 0% to 1.00%, Ni: 0% to 3.00%, and a remainder consisting of Fe and impurities. A structure includes, by area radio, tempered martensite of 90% or more. The prior austenite grain size number is No. 12.5 or higher. The presence density of iron-based carbide having an equivalent circle diameter ranging from 0.15 μm to 0.50 μm ranges from 0.40 pieces/μm2 to 2.00 pieces/μm2.
摘要:
A process for effecting an annealing treatment of a spheroidal or lamellar graphite cast iron pipe. While the pipe is driven in rotation about the axis of the pipe, it is suspended substantially horizontally as it issues from the centrifugal casting machine and the pipe is partly immersed in a bath of metal at the desired temperature. An installation for carrying out this process comprises an elongate vessel having a horizontal axis and containing a bath of molten metal at the required temperature. A withdrawable device is provided outside the bath for suspending the pipe in a substantially horizontal position and plunging the pipe partly in the bath while driving the pipe in rotation about the axis of the pipe.
摘要:
A processing apparatus forms a metallic material such as steel. The apparatus includes a heating tub, spray nozzles, a cooling tub, and a circulator. The heating tub heats the steel to equal to or higher than the modification point of the steel. The spray nozzles cool the steel processed by the heating tub to lower than the modification point, by contacting liquid metal sodium onto the steel. The cooling tub stores the liquid metal sodium, soaks the steel processed by the spray nozzles, and cools the steel. The circulator 20 circulates the liquid metal sodium so that the liquid metal sodium flows in the same direction as the steel in the cooling tub 3.
摘要:
An apparatus for quenching a metallic material such as steel is provided. The apparatus includes a heating furnace, a liquid metal sodium chamber, a gas cooling chamber, and a liquid metal sodium removal chamber. The heating furnace heats the metallic material to more than 700null C. The liquid metal sodium chamber includes liquid metal sodium, and the metallic material is cooled approximately to between 100null C. and 250null C. The inert gas chamber includes inert gas such as nitrogen or argon, and the metallic material is cooled approximately to room temperature. In the liquid metal sodium removal chamber, the liquid metal sodium remaining on the metallic materials is removed by using vapor, mist, and water.
摘要:
A heating bath including molten metal is situated at an entry into a hot roll mill such that the metal stock entering the hot roll mill passes through the heating bath to acquire heat therefrom. A cooling bath including molten metal is situated at an exit from the hot roll mill such that the metal stock exiting from the hot roll mill passes through the cooling bath delivering heat thereto. The molten metal in each of the baths is caused to flow counter to the direction of passing of the metal stock therethrough to form within each bath a hotter fraction and a cooler fraction of the molten metal. The molten metal is circulated between the heating bath and the cooling bath so that a hottest fraction of the molten metal in the cooling bath is transferred to the heating bath and a coolest fraction of the molten metal in the heating bath is transferred to the cooling bath.
摘要:
A galvannealed steel sheet includes: a steel sheet; a coating layer on a surface of the steel sheet; and a mixed layer formed between the steel sheet and the coating layer, in which the mixed layer includes a base iron portion having fine grains having a size of greater than 0 μm and equal to or smaller than 2 μm, a Zn—Fe alloy phase, and oxides containing one or more types of Mn, Si, Al, and Cr, and in the mixed layer, the oxides and the Zn—Fe alloy phase are present in grain boundaries that form the fine grains and the Zn—Fe alloy phase is tangled with the base iron portion. [Mn]+[Si]+[Al]+[Cr]≧0.4 (Expression 1)