Abstract: A stainless cast steel of ferrite-austenite two-phase structure having high corrosion fatigue strength and high pitting corrosion resistance containing in terms of % by weight, up to 0.1% C, up to 2.0% Si, up to 2.0% Mn, 22.0-27.0% Cr, 5.0-9.0% Ni, 1.1-2.5% Mo, 0.5-2.5% Cu, 0.5-2.0% Co and 0.5-2.0% V, the steel further containing, if desired, one or more kinds of 0.5-2.0% Nb and/or Ta and 0.01-0.5% Ti, the balance being substantially Fe and inevitable impurities.

Abstract: A roll, for high temperature service in continuous slab casting, has having its sleeve shrinkage-fitted onto the roll shaft under tight contact state, wherein the alloy composition of the sleeve as expressed in % by weight is as follows.The principal components are:C: 0.20 or lessSi: 0.1 to 2.0Mn: 0.1 to 2.0Cr: 10 to 14N: 0.02 to 0.20; providedC+N: 0.30 to 0.35; andin addition to the principal components specified above, permissably one or more components beingNi: 0.1 to 5.0Mo: 0.1 to 2.0V: 0.01 to 0.3W: 0.1 to 0.3, andthe balance is Fe.

Abstract: A reactor tube for thermally cracking or reforming hydrocarbons comprising a tube member made of Fe-Cr-Ni heat resisting material and a covering layer of self-fluxing alloy fusing to the inner surface of the tube member, the covering layer made of heat resisting material free from Ni or with a low Ni content. The tube member is manufactured by centrifugal casting, and the covering layer is formed by applying the self-fluxing alloy powder by scattering with or without thermit agent or spraying the alloy to the inner surface of the tube member.

Abstract: A reactor tube for thermally cracking or reforming of hydrocarbons wherein a reacting layer contacting hydrocarbons is made of heat resisting steel comprising, in terms of % by weight, 0.3 to 1.5% C, up to 3% Si, 6 to 15% Mn, 20 to 30% Cr, up to 3% Nb, up to 0.15% N, the balance being substantially Fe and a covering layer which covers the said reacting layer is made of Fe-Cr-Ni heat resisting steel and is fused to the reacting layer at their boundary.

Abstract: A reactor tube for thermally cracking or reforming hydrocarbons comprising an outer tube member made of Ni-containing heat resisting material and having enhanced mechanical strength with a large wall thickness, and an inner tube member of small wall thickness fitted in the outer tube member and made of heat resisting material free from Ni or with a low Ni content. The inner and outer tube members have been subjected to a diffusion treatment with a thin coating of Ni-P solid solution provided at the junction therebetween and thereby bonded together.

Abstract: A method of refining the structure of the straight tube portions at the ends of an elbow made of cast stainless steel characterized in that a cast stock tube of a cast austenitic stainless steel with its chemical composition so adjusted as to have the ferrite phase mixed in in the proportion of 5-40% is formed, with the straight tube portions at its ends made larger or smaller than the specified dimension; the said straight tube portions are formed roughly to the specified dimensions by subjecting them to a plastic deformation either by a process of contraction or expansion, and thereafter, the tube thus formed is heated at 1,000.degree.-1,200.degree. C., and then, quenched.