Abstract No. 72. Complexity of reception inspection for casting powders at Dillinger Steel Works

Transcription

1 Abstract No. 72 Complexity of reception inspection for casting powders at Dillinger Steel Works Dr. Hans-Uwe Schmitz, Ingo Scher, AG der Dillinger Hüttenwerke, Dillingen, Germany The reception inspection of incoming materials directly used in production is an essential prerequisite to achieve high quality final products. Moreover, it is an important factor for an optimized and economical production cycle. Thus, the reception inspection usually is part of the implemented quality management system. Howevere, in practice it is often a difficult task to fulfil because of restrictions in time, costs and stockyard capacities. Normally sophisticated logistics are required to have the reception inspection finished in time and compared to material specifications prior to usage of the material. Beside the classical chemical analysis and determination of physical parameters, we currently observe an increasing demand for more detailed compound informations. These knowledge could be deduced for example from phase analytical data applying X-Ray diffractometry. In this presentation the complexity of reception inspections is adressed on the basis of the example casting powder inspection used at Dillinger Steel Works.

2 Complexity of reception inspection for casting powders at Dillinger Steel Works H.-U. Schmitz, I. Scher (AG der Dillinger Hüttenwerke, Werkstr.1, Dillingen, Germany) Cetas-Conference; Düsseldorf; ) Introduction / Motivation Overview 2) Sampling 3) Procedures 5) X-Ray Diffraction (XRD) 6) Approval Procedure 7) Summary - Concluding remarks Cetas-Conference; Düsseldorf;

3 Quality management system Casting powder influences the quality of the product The quality of the casting powder affects the casting process We have to control the product quality and aim for a stable process The quality of the casting powder has to be checked prior to use need reception inspection 1) Motivation Cetas-Conference; Düsseldorf; Important aspects related to reception inspection and logistics: stockyard capacity representative sampling procedure 1) Motivation appropriate anal. methods (precision, trueness, analysis time...) time management: analysis ready before use approval procedure (7/24/365) logistics: transport..., correct material on-site in time costs Cetas-Conference; Düsseldorf;

4 Sampling of casting powder from the stone magazine Accompanying note for sampling of casting powder faxed from storaeg yard to the laboratory ; Additional notes from the laboratory staff uncluding reference number (sample and report) Sampling of casting powder from the storage yard Sealed big bag after sampling Sampling of casting powder at the storage yard Sealed Big Bag bevor sampling Sampling of casting powder from the storage yard Transfer of the sample to a pre labeled sample bag 2) Sampling Sampling of casting powder from the storage yard Big Bag labeled by the supplier Sampling of casting powder from the storage yard Sampling of one Big Bag per delivery by shovel Total sampling weight: about 12 kg Cetas-Conference; Düsseldorf; Grinding < 0,063 mm Preparation and Analysis of Casting Powder As delivered Grinding < 0,125 mm Cetas-Conference; Düsseldorf; ) Procedures XRD AAS C/S XRF Sieving H2O

5 4) Chemical analysis: 3 major observations Systematic difference from lab-to-lab Measurement uncertainty of DH-lab Changes in product Cetas-Conference; Düsseldorf; Measurement uncertainties for routine analysis in DH-lab Measurement uncertainties determined from calibration curves (w-%) CaO SiO2 Fe2O3 MnO P2O5 Al2O3 MgO 0,25 0,3 0,02 0,005 0,005 0,1 0,05 TiO2 F Na2O K2O C ges. S H2O 900 C 0,008 0,2 0,15 0,012 0,15 0,008 0,1 Cetas-Conference; Düsseldorf;

6 Diff (Gew-%) 0,8 0,6 0,4 0,2 0-0,2-0,4-0,6 (product homogeneity) Cetas-Conference; Düsseldorf; LOI LOI C(tot) C(tot) Inter-laboratory deviation (DH-lab / supplier) C(free) C(free) SiO2 SiO2 Fe2O3 Fe2O3 Al2O3 Al2O3 CaO CaO Cetas-Conference; Düsseldorf; MgO MgO Na2O+K2O Na2O+K2O Round robin on one casting powder sample between supplier and DH (differences) F- F- MnO MnO S S CaO/SiO2 CaO/SiO2 H2O H2O

7 delta C % C difference (measured-target) [w-%] 10 9,5 C (%) 8,5 8 7,5 7 6, ,8 0,6 0,4 0,2 0 0,2 0,4 0,6 0, C (bigbag analysis during casting; difference to target content) Cetas-Conference; Düsseldorf; comparison of C analysis in batch with process values in plenary trial batch batch analysis process analysis -1 Cetas-Conference; Düsseldorf;

8 5) X-ray diffraction spectrometry (XRD) XRD-spectra: DH standard casting powders from 2 suppliers Cetas-Conference; Düsseldorf; ) XRD: several shipments of one supplier quartz reflex quartz reflex Cetas-Conference; Düsseldorf;

9 5) XRD: several shipments of one supplier wollastonite reflex (polymorphismus: different modification monocline and tricline) Wollastonite 2m( monocline) Wollastonite 1tc ( tricline) Cetas-Conference; Düsseldorf; ) XRD carbon component (grafite and amorphous carbon coke) graphite reflex amorphous Carbon (coke) Cetas-Conference; Düsseldorf;

10 5) XRD: several shipments of casting powder from one supplier ( no detectable grafite) major reflex for graphite 2Theta = Cetas-Conference; Düsseldorf; Arrival of material (status blocked) sampling / analysis Cetas-Conference; Düsseldorf; ) Approval procedure Comparison of parameters with specification and XRD not approved: material blocked Check by experts Reclamation: Matrial blocked Contact to supplier Approval Usage of material Approval Usage of material

11 it is an important part of QM high demands on classical analytical work includes component informations (XRD fingerprints) fast analysis approval before use approval procedure (7/24/365) logistics: stockyard, transport, correct material on-site in time costs 7) Summary - Concluding remarks Reception inspection (for casting powder) is complex because: Cetas-Conference; Düsseldorf; Thank you Cetas-Conference; Düsseldorf;