finishing-semi-finished-partsThe characteristics of semi-finished parts can makethe finishing process extremely complicated. pressure 0 tensionHypothetical pattern oftangential residual stressesin the part blankGrain size and orientationDistribution and size of hardphases (e.g. carbides)Chipping: Tool wear, chatter marks, galling, undesirable chip shapes, surfacequality (e.g. orange-peel effect), residual stresses near the surface, warping, tendency to micro-cracking (comma cracks), grinding cracks (hot cracks), carbides breaking out of the surface, grain boundaries cracking open.Forming, straightening: Cracking/fractures, orange-peel effect under influence ofgrain size and grain orientation.Welding: Hot cracking, delayed cracking (stress relief cracking) in stellite hardfacing on the contact surfaces of shrouds, welding to attach labyrinth tipsEtching, chemical and electro-chemical dissolving and boring:Inter-granular corrosion, selective material removal (e.g. release of carbides),cracking (stress corrosion cracking) whenremoving oxide coatings,stripping coatings,opening cracks before penetrant testingHeat treatment: Warping, cracking (hot cracks).Quality assurance: Testability using ultrasound; coarse grain and uneven grain sizesincrease the scattering and minimize the detectability of flaws.Testing using X-rays to measure diffraction around coarse grain in cast parts.Hardening phases: degree of developmentTrace elements/segregations and their distributionTypische Halbzeugmerkmale die sichauf die nachfolgenden Fertigungsschritteerschwerend auswirken kรถnnen.Typical material-related problems in finishing and quality assurance: