Zirconium

Specification detail with sources

ASTM B550 defines Grade 702 chemistry in a way certificate reviewers should hold onto: R60702 requires zirconium plus hafnium combined at 99.2 percent minimum while allowing hafnium itself up to 4.5 percent, so hafnium content, not a bare zirconium purity figure, is the line a mill certificate has to answer. Density adds a second checkable value, since zirconium’s 6.5 grams per cubic centimeter makes it by far the lightest metal handled alongside the refractory routes here, roughly a third of tungsten’s 19.3.

Beiyu Titanium supplies Grade 702 and Grade 705 to the envelope published further down this page, and quotes each item from the buyer’s drawing and the standard the order names. Every order runs the same controls as Beiyu’s other lines: six RFQ fields reviewed first, grade, standard, dimensions, tolerance, surface condition and inspection scope, then chemical composition checked through one of two laboratory routes, dimensional inspection against the ordered tolerance, and MTC with EN 10204 3.1 under heat number traceability by order scope.

Supply envelope for zirconium

Zirconium for chemical service is ordered by grade rather than by element, since the two grades supplied are bought for different reasons: unalloyed ZR702 and the niobium bearing ZR705 for higher strength.

The grades carry UNS R60702 and UNS R60705. Industrial zirconium is supplied with its natural hafnium content left in, since removing hafnium is done for neutron absorption reasons rather than for corrosion ones; nuclear grades are the ones where hafnium is restricted, and chemical plant work almost never calls for them. Zirconium tube is produced to the same grade family and quoted separately. The table gives the ranges Beiyu Titanium supplies to; work outside them is quoted against the drawing.