Abstract: A corrosion-resistant steel tube such as a sheath heater steel tube and boiler tube which exhibit improved resistance to dry corrosion under high temperature dry-corrosive conditions in the presence of chlorides is disclosed. The steel consists essentially of, in % by weight:______________________________________ C: not more than 0.05%, Si: 0.1-2.0%, Mn: not more than 2.0%, Cr: 18-26%, Ni: 16-30%, ______________________________________at least one of Mo: 0.5-4.0%, W: 0.01-4.00%, andV: 0.01-4.00%,N: 0-0.25%,(Ti+Nb): 0-1.5%, andthe balance iron and incidental impurities.

Abstract: A facedown-type semiconductor pressure sensor has a Si sensing element including a diaphragm, a spacer, and a piezoresistive device embedded in the diaphragm, and a pedestal. The spacer, which is positioned between the semiconductor substrate and the pedestal, has a photolitho-graphically etched hole such that the sensing element, the hole and the pedestal define a sealed chamber. The sealed pressure chamber is substantially aligned with the diaphragm.

Abstract: A self regulating heater comprises a non-conductive, magnetic core having a coil wound about it and providing pole pieces extending into contact or very near contact with a surrounding ferromagnetic member which in turn may be surrounded by and in intimate contact with a non-magnetic low resistance member; the magnetic member having an effective Curie temperature at the temperature to be maintained.