PMI Inspection Workflow for Stainless Steel and Nickel Alloy Orders

Shaanxi Shangyou Stainless Steel Co., Ltd. coordinates positive material identification when the purchase order or project inspection plan requires an additional alloy check. The order review identifies the grade, UNS designation, product form, number of heats, lot structure, sampling level, test method, acceptance basis and required report format. PMI may be applied to stainless steel pipe, plate, bar, fittings, profiles or nickel alloy products. A statement such as '100% PMI' is used only when the agreed population has been individually tested and the result is traceably recorded. Otherwise, the exact sampling plan is stated.

Handheld XRF is widely used to compare elements such as chromium, nickel and molybdenum, making it useful for separating many common alloy families. It does not measure carbon reliably, so grade distinctions that depend on low carbon or other light elements may require optical emission spectroscopy, mill documentation or laboratory analysis. Test locations are selected according to the plan and prepared where needed to reduce interference from scale, coating or contamination. Instrument verification and calibration status are checked, and the reading is linked to the physical heat, piece or package. Any out-of-acceptance reading is segregated and investigated before release.

Buyers should state whether PMI is required by heat, lot, piece or percentage; which elements or grade family must be confirmed; the permitted method; the acceptance criteria; the witness requirement; and the report language. PMI should be reviewed together with the original MTC, physical markings, heat-number continuity and any mechanical, corrosion or NDT reports required by the project. For duplex, super duplex, nickel alloys or mixed-material packages, the inspection plan can also define a material-verification map so the customer can connect each result to the final packing list.

CTA: Send the grade list, product forms, quantities and required PMI sampling level for an inspection-plan review.