Abstract: A vacuum furnace for heat treatment comprises a heating furnace proper, pre-exhaust chambers, one adapted to feed a workpiece into the furnace proper therefrom and the other adapted to discharge the workpiece out of the oven proper thereinto, vacuum valves for partitioning between the oven proper and the respective pre-exhaust chambers, and a line assembly for deliver of the workpiece from the feed chamber into the discharge chamber through the furnace proper. A heating chamber forming part of the furnace proper is positioned on the upper part above the deliver line assembly, and an externally operable elevating means is disposed in the furnace proper. The work pieces carried by the delivery line assembly, and lifted to the heating chamber where it is heated.

Abstract: A continuous hardening device of steel plate of a type wherein steel plate is continuously cooled and hardened by cooling water. The cooling water is continuously supplied into and exhausted out of a water vessel (10) provided in the path of the steel plate for cooling the same. A plurality of rollers (16, 18) supporting the steel plate on the upper and lower sides thereof to feed the same and a plurality of paddle wheels (32, 34) having axial shafts disposed in parallel with the rollers (16, 18) are provided in the water vessel (10). Each paddle wheel (32, 34) is disposed between adjacent rollers and close to the steel plate, and stirs and causes the cooling water to flow along the surface of the steel plate with a predetermined relative speed maintained between the cooling water and the steel plate. The cooling and hardening efficiency of the steel plate is substantially improved by the relative movement of the cooling water and the steel plate.

Abstract: Aluminum base bearing alloys of increased resistance to fatigue and/or anti-seizure property suitable for use with internal combustion engines. One of the aluminum bearing alloys of this kind is an alloy of the Al-Pb-Sn-Cu-Si system having added thereto at least one element selected from the group consisting of Ni, Mn, Cr, V, Mg, Ti, Zn, Co and Zr, and the other aluminum bearing alloy of an improved type is an alloy of the aforesaid Al-Pb-Sn-Cu-Si- (added further with at least one of Ni, Mn, Cr, V, Ti, Zn, Co, Zr) and further added thereto at least one element selected from the group consisting of Sb, Bi, Cd and In.

Abstract: Steel having a structure of ferrite and tempered martensite and exhibiting excellent vibration attenuation characteristic is manufactured by the steps of forming a solid solution of steel consisting essentially of 0.02.about.0.016% by weight of carbon; less than 0.6% by weight of silicon; 0.5.about.1.5% by weight of manganese; either one or more of 5.about.15% by weight of chromium and 2.about.9% by weight of tungsten; either one or both of 0.03.about.2% by weight of aluminum and 0.1.about.5% by weight of cobalt; less than 1.5% by weight of copper, if necessary, and the balance of iron; heating and keeping for a desired time period the alloyed steel in a temperature range in which austenite and ferrite coexist; cooling the steel so as to transform austenite to martensite; and tempering the steel at a temprature of from 400.degree. C. to a temperature below a transformation point thus forming a structure of ferrite and martensite. Steel incorporated with copper is suitable for precipitation hardening.

Abstract: An apparatus for injecting a gas-laden refining agent into molten metal in a ladle comprises a multinozzle lance which has a plurality of introduction tubes in a lance body and a plurality of nozzles mounted in the lance body and connected to the introduction tubes, the nozzles opening substantially tangentially to an outer circumferential surface of the lance body. Each of the nozzles is molded of boron nitride and in the form of a conical taper which becomes progressively smaller in diameter toward the outer circumferential surface of the lance body. There is a system for independently distributing the gas-laden refining agent under pressure through a plurality of feed pipes which are connected to the introduction tubes, respectively, of the multinozzle lance.