Q420qD bridge plate supplied for box-girder project

Bridge plate deliveries move to the rhythm of segment fabrication. This batch of Q420qD feeds a steel box-girder job: Z25 through-thickness properties, plate-by-plate UT, eight batches sequenced to the segment plan — every delivery date answering to a jig on the fabricator's floor.

Three add-ons that define the order

Beyond grade and size, the contract pinned three items: Z25 properties (webs welded to flanges, lamellar-tearing territory), UT to GB/T2970 Class II plate by plate, and -20°C impact single values guaranteed. Each clause maps to its own inspection line — mill certificate plus arrival re-check, certificates filed by heat number into one register.

Working with the supervisor

Bridge projects inspect with witnesses: sampling locations, specimen counts and the test house are agreed before work starts. We stage the coupons ahead of each witness visit; after sealing, samples travel with the supervisor to the lab. The process costs a few days and buys a one-pass acceptance — the next trade keeps moving.

From here the plates go to the fabricator's cutting and assembly bays. Our delivery ends at the cut list, but the heat-number register travels with the project to opening day. Bridges are hundred-year works; the traceability chain never gets a day off.