Sulfuric acid is a tricky chemical to deal with since its corrosivity varies with concentration, temperature, impurities, and velocity; sometimes in unexpected ways. I suggest you get a detailed reference that covers sulfuric acid and materials of construction selection such as MTI Publication 1: Materials Selector for Hazardous Chemicals: Sulfuric Acid. Using this reference and your conditions, several alloys might work. These include tantalum, platinum, zirconium, alloy 825, and Hastelloy B or D. The manufacturers of these specific alloys would also be an excellent source for further information and corrosion resistance data.