納米隔熱彩板

過去，鋼卷取過程中的內(nèi)應(yīng)力計算都是以鋼卷為彈性厚壁圓筒或彈性組合圓筒為基礎(chǔ)的。事實(shí)上，彩鋼卷的厚度一般較大，而且彩鋼卷沿圓周具有明顯的非圓形特征。彩鋼卷按圓曲線處理，計算誤差較大。
因此，在熱軋彩鋼板卷取過程中，隨著帶鋼厚度的增加，帶鋼沿周向的非圓特性更加明顯。然而，以往采用的具有周向?qū)ΨQ性的封閉圓柱模型不僅與帶材的實(shí)際狀態(tài)偏差較大，而且不能準(zhǔn)確預(yù)測層間滑移。根據(jù)熱軋卷取工藝的設(shè)備和工藝特點(diǎn)，采用螺旋開口圓筒模型，提出了一套適用于彩鋼熱軋卷取的鋼卷內(nèi)應(yīng)力分布模型，考慮到卷取過程中沿周向應(yīng)力和變形的不均勻性，以及卷頭線圈與卷筒接觸不完全的特點(diǎn)，并給出了相應(yīng)的層間滑移判斷條件，開發(fā)了相應(yīng)的鋼卷內(nèi)部應(yīng)力和層間滑移預(yù)測軟件，并應(yīng)用于生產(chǎn)實(shí)踐。 
在卷取過程中，隨著卷徑的增加，某一層彩鋼卷的徑向壓力增大；對于彩鋼卷內(nèi)層，即頭部部分增加較多，層間結(jié)合概率明顯增大；但對于卸料卷，環(huán)向應(yīng)力在鋼卷內(nèi)層的徑向應(yīng)力隨層內(nèi)壓力的增加而減小，而層間的周向應(yīng)力往往隨著層間壓力的減小而減小，線圈中間的一些層

大值減小。如果初始卷取張力較大，可能出現(xiàn)負(fù)值。 
對于軟質(zhì)薄的彩鋼板卷，當(dāng)彩鋼板卷的張力小于初始設(shè)定值而沒有抱箍時，鋼卷內(nèi)部的徑向應(yīng)力過小，容易導(dǎo)致層間滑移，造成卷料塌陷。雖然采用較大的張力可以避免卷盤塌陷缺陷，但對于彩鋼卷頭來說，卷取張力過大，導(dǎo)致前幾卷卷產(chǎn)生切向壓應(yīng)力，當(dāng)鋼卷在提升或放置過程中受到?jīng)_擊干擾時，往往會出現(xiàn)心形缺陷； 
針對目前采用的錐形控制的硬核卷取技術(shù)，當(dāng)鋼卷出筒時，線圈內(nèi)層向內(nèi)收縮。當(dāng)拉錐曲線下降過大時，拉應(yīng)力過大有可能引起抽芯。

In the past, the calculation of the internal stress of steel coilin coiling process was based on the steel coil as elastic thickwall cylinder or elastic combination cylinder. In fact, thethickness of color steel coil is generally larger, and the colorsteel coil has obvious non-circular characteristics along thecircumference. If the color steel coil is treated according to thecircular curve, the calculation error will be large.

Therefore, with the increase of the strip thickness, thenon-circular characteristics of the strip along the circumferentialdirection are more obvious in the coiling process of the hot-rolledcolor steel coil. However, the closed cylinder model withcircumferential symmetry used in the past not only has a largedeviation from the actual state of the strip, but also can notaccurately predict the interlayer slip. Based on the e andprocess characteristics of hot rolling coiling process, a set ofinternal stress distribution model of steel coil suitable for hotrolling color steel coiling is proposed by adopting spiral openingcylinder model, considering the nonuniformity of stress anddeformation along circumferential direction during coiling processand the feature of incomplete contact between coil head coil anddrum, and corresponding judgment conditions of interlayer slip aregiven The corresponding prediction software of internal stress andinterlayer slip of steel coil is developed and applied toproduction practice.
In the coiling process, with the increase of coil diameter, theradial pressure of a certain layer of color steel coil increases;for the inner layer of color steel coil, that is, the head partincreases more, which results in the obvious increase of thebonding probability between layers; however, for the unloadingcoil, the radial pressure decreases layer by layer from the insideto the outside; and the circumferential stress law is different,The minimum value often occurs in a certain layer inside the coil,and the circumferential stress at the head of the color steel coildecreases with the increase of the pressure, and some layers in themiddle of the coil decrease the maximum. If the initial coilingtension is large, negative value may appear.
For the soft and thin color steel coil, when the tension of thecolor steel coil is less than the initial set value withouthooping, the radial stress inside the coil will be too small, whichwill easily lead to slippage between layers and cause coilcollapse. Although the large tension can be used to avoid the coilcollapse defect, for the head of the color steel coil, the coilingtension is too large, resulting in the tangential compressivestress on the first few coils, When the steel coil is disturbed byimpact during lifting or placing, heart-shaped defects oftenoccur;
In view of the current hard core coiling technology with conecontrol, when the coil is discharged from the drum, the inner layerof the coil shrinks inward. When the taper curve of tension dropstoo large, the core pulling is likely to be caused by the too largetensile stress.