Common txheej defects ntawm seamless tubes (smls):

1. Folding defect
Kev faib tawm tsis tu ncua: Yog tias pwm slag tseem nyob hauv cheeb tsam ntawm qhov chaw nruam casting slab, qhov sib sib zog nqus folding tsis xws luag yuav tshwm sim rau sab nrauv ntawm lub raj dov, thiab lawv yuav muab faib ua longitudinally, thiab "blocks" yuav tshwm sim ntawm qee qhov chaw ntawm qhov chaw. . Lub folding qhov tob ntawm lub dov raj yog hais txog 0.5 ~ 1mm, thiab kev faib folding kev taw qhia yog 40 ° ~ 60 °.

2. Loj folding tsis xws luag
Longitudinal tis: Crack defects thiab loj folding defects tshwm nyob rau saum npoo ntawm nruam casting slab, thiab lawv muab faib longitudinally. Feem ntau ntawm cov folding qhov tob ntawm qhov chaw ntawm seamless steel raj yog li 1 txog 10 hli.

3. Me me tawg tsis xws luag
Thaum kuaj seamless steel raj, muaj qhov tsis xws luag ntawm cov phab ntsa sab nrauv ntawm lub cev yeeb nkab uas tsis tuaj yeem pom los ntawm qhov muag liab qab. Muaj ntau yam me me folding tsis xws luag nyob rau saum npoo ntawm seamless steel yeeb nkab, qhov tob tshaj plaws yog hais txog 0.15mm, nto ntawm seamless steel yeeb nkab yog them nrog ib txheej ntawm hlau oxide, thiab muaj ib tug decarburization txheej nyob rau hauv cov hlau oxide, qhov tob yog li 0.2 hli.

4. Linear defects
Muaj cov kab tsis xws luag nyob rau sab nrauv ntawm lub raj seamless steel, thiab cov yam ntxwv tshwj xeeb yog qhov tob tob, qhov qhib dav, pom hauv qab, thiab qhov dav tsis tu ncua. Cov phab ntsa sab nrauv ntawm qhov hla ntu ntawm cov yeeb nkab seamless steel tuaj yeem pom nrog khawb nrog qhov tob ntawm <1mm, uas yog nyob rau hauv cov duab ntawm ib tug zawj. Tom qab kev kho cua sov, muaj oxidation thiab decarburization ntawm ntug ntawm qhov zawj ntawm cov yeeb nkab.

5. Scarring tsis xws luag
Muaj cov qhov dej ntiav ntiav nyob rau sab nrauv ntawm lub seamless steel raj, nrog ntau qhov sib txawv thiab thaj chaw. Tsis muaj oxidation, decarburization, thiab aggregation thiab inclusions nyob ib ncig ntawm lub qhov; cov ntaub so ntswg nyob ib ncig ntawm lub qhov dej yog squeezed nyob rau hauv high kub, thiab yas rheological yam ntxwv yuav tshwm sim.

6. Quenching tawg
quenching thiab tempering tshav kub kev kho mob yog nqa tawm nyob rau hauv seamless steel raj, thiab longitudinal nplua kab nrib pleb tshwm nyob rau sab nrauv, uas yog faib nyob rau hauv ib daim hlab nrog ib tug tej yam dav.

Common sab hauv defects ntawm seamless raj:

1. Convex hull defect
Macroscopic nta: Sab hauv phab ntsa ntawm seamless steel raj tau random faib me me longitudinal convex defects, thiab qhov siab ntawm cov me me convex defects yog hais txog 0.2mm mus rau 1mm.
Cov yam ntxwv ntawm microscopic: Muaj cov saw zoo li cov xim dub-grey suav nrog ntawm tus Tsov tus tw, nruab nrab thiab ib puag ncig ntawm lub hau npog ntawm ob sab ntawm phab ntsa sab hauv ntawm ntu ntu ntawm cov yeeb nkab steel seamless. Hom dub-grey saw no muaj calcium aluminate thiab ib qho me me ntawm cov oxides (hlau oxide, silicon oxide, magnesium oxide).

2. Ncaj tsis ncaj
Cov yam ntxwv ntawm Macroscopic: Ncaj-hom tsis xws luag tshwm sim hauv seamless steel hlab, nrog rau qhov tob thiab dav, zoo ib yam li khawb.

Cov yam ntxwv ntawm microscopic: Cov khawb ntawm cov phab ntsa sab hauv ntawm qhov hla ntu ntawm seamless steel raj yog nyob rau hauv cov duab ntawm ib tug zawj nrog ib tug tob ntawm 1 mus rau 2 cm. Oxidative decarburization tsis tshwm sim ntawm ntug ntawm qhov zawj. Cov ntaub so ntswg ncig ntawm qhov zawj muaj cov yam ntxwv ntawm cov hlau rheology thiab deformation extrusion. Yuav muaj microcracks vim sizing extrusion thaum lub sij hawm sizing txheej txheem.