1 6104 INCORRECT ROUGHNESS – GRINDING but the roughness of the as cast surface(s) is not according to the requirements. The defect appears mostly together with all other type of defect (No 7503) as is lack of material and 5601, 5602 and 5603 as extra material. The defect can be repaired by extra grinding (if some extra section thickness is present) and it can be performed without creating a dimensional non-conformity. If this is not possible, the customer can be informed and asked for an acceptance (filing a deviation request, DR). 6 7 II.3 PICTURES II.3.1 Principle II.3.2 Castings Rough surface – too much grinding compared to other surfaces Rough surface – too much grinding compared to other surfaces Rough surface – too much grinding Rough surface – excessive grinding flash II.3.3 NDT tests 8 III. EXPLANATION III.1 EXPLANATION III.2 REQUIRED INFORMATION III.1 EXPLANATION This defect is due to excessive grinding / fettling (mostly hand grinding / fettling) of the area were risers were located. It is also present in the area where ingates and vents were located and sometimes chills. It can also appear when thick flash is removed. It will be more pronounced when it concerns non-flat surfaces. It is difficult to grind with a result equal to the curves base surface. Small round castings due have the most frequent problem with this. Many times, it is a fake-defect, especially when the grinded surfaces are very smooth, much more than the neighboring non-grinding surfaces. This problem can sometimes be solved by extra shot blasting, which equalize the appearance. It can happen that the surface can be corrected by extra grinding and or extra machining operation, but this extra operation may not lead to dimensions not matching the requirements (dimension and tolerance). In case of non-conformity, inform the customer and request for a deviation (DR) in roughness or dimensions. 9 III.2 REQUIRED INFORMATION IV. LITERATURE REQUIRED INFORMATION PRODUCTION Material Melting & pouring Chemistry (C, Si, Mn, S, P) Highest temperature in furnace Chemistry (alloying elements) Time on temperature (> Tg) Chemistry (residual elements) Number of taps Other: Temperature between taps Metallurgical treatment: type Moulding Result O-, H-, N-content Green sand: clay, burnt clay x Result Al-, Ti-content Green sand: green strength x Result Mg-, RE-content Green sand: strength x Time treatment to pouring Green sand: water content x Pouring temperature Green sand: permeability x Pouring time Green sand: sand/metal ratio x Thermal analysis No-bake sand: type of sand x Ladles No-bake sand: sieve analysis x Heat treatment No-bake sand: shape of sand x Heat treatment cycle No-bake sand: LOI x Cooling No-bake sand: LOI * x Condition cooling device No-bake sand: S-content x No-bake sand: N-content x Shot blasting / fettling No-bake sand: P-content x Shake out temperature No-bake sand: Acid demand x Type of shot blasting No-bake sand: sand/metal ratio x Type of PS / riser removing No-bake chemicals x Type of fettling Type of coating & liquidiser x Coating thickness / layers x Quality control Coating drying x Report NDT-test x Ceramic sand: type of sand x Tensile test result Ceramic sand: mould thickness Hardness test result Ceramic sand: drying type & time x Charpy-V test result Ceramic sand: wax-removing x Other tests: roughness x Ceramic sand: pre-heating x Pouring system & risers & chills Metal mould: type and thickness Pouring system design Metal mould: coating type x First metal Metal mould: coating thickness x Venting Mould: pre-heating x Pouring box Other info Type of risers Weather conditions: humidity Type of chills Weather conditions: temperature Type of sealing Fettling procedure x 10 Process Control Manual G Henderieckx, Gietech BV, soft copy Rejection & Rework manual G Henderieckx, Gietech BV, soft copy
铸造文库