本文選題：冷軋工作輥 + 水淬油冷�。� 參考：《機械科學研究總院》2016年碩士論文

【摘要】：當今很多材料加工流程中都會涉及到軋制工藝,軋輥的性能很大程度上決定著產(chǎn)品質(zhì)量。作為軋機上的關(guān)鍵部件,軋輥在運轉(zhuǎn)時會受到來自外界的多種應(yīng)力,同時這些力量的方向和力度都沒有規(guī)律可循,所以軋輥的使用壽命是有限的。軋輥的壽命主要取決于軋輥的表面硬度、有效淬硬層深度和強韌性能,本文研究的小規(guī)格MC3冷軋工作輥主要應(yīng)用于軋制不銹鋼板帶,其應(yīng)具備多種優(yōu)良的機械性能,包括硬度、韌度以及強度,表面硬度應(yīng)達到HRC60,以防止軋輥在工作過程中失效。冷軋工作輥常用整體淬火熱處理工藝,軋輥若要滿足上述性能,淬火冷卻過程宜采用水淬油冷工藝方式,然而其工藝參數(shù)受人為影響較大,MC3冷軋工作輥水淬油冷工藝參數(shù)的不穩(wěn)定,造成軋輥的組織性能產(chǎn)生相應(yīng)變化,加上生產(chǎn)時各方壓力對其產(chǎn)生的損害,最后的結(jié)果就是軋輥很快不能正常工作,嚴重時會導致停產(chǎn)。針對該問題,本文對冷軋工作輥水淬油冷工藝參數(shù)進行深入研究。本文根據(jù)冷軋工作輥水淬油冷工藝特點,利用SEM掃描電子顯微鏡、金相顯微鏡、洛氏和維氏硬度計、沖擊試驗機等,利用設(shè)備檢測組織性能,進而探討影響軋輥使用壽命的各種外部和內(nèi)部因素,并以此為依據(jù)提出了解決方案。同時也從工藝步驟上分析水淬時長如何影響材料的性能,繼而對熱處理流程做出改進。研究結(jié)果表明:(1)非正常失效的軋輥,硬度梯度在淬硬層周圍較陡峭,金相組織變化明顯;正常失效的軋輥硬度梯度較平緩,是熱處理工藝設(shè)計欲達到的效果;(2)材料中彌散碳化物的比例和水淬時長有著一定的正比關(guān)系,淬火時形成片狀馬氏體的比例以及淬硬層深度也是如此。帶來的結(jié)果是鋼材硬度的加大。但是硬度梯度卻不再那么大,曲線較緩和;(3)試塊隨著水淬時間的增加,沖擊性能逐漸降低,并且隨著表面距離的增加,相同位置沖擊韌性下降趨勢逐漸增大。鍛后的MC3試塊經(jīng)870℃球化退火,調(diào)質(zhì)處理,水淬210s后油冷,165℃回火處理后,表面硬度達到61HRC。與失效軋輥的組織性能對比后,試驗試塊在滿足高硬度的同時,又具有平緩的硬度梯度分布和較好的心部基體韌性,說明水淬210s油冷是合適的熱處理工藝參數(shù)。本文的研究結(jié)果滿足了冷軋工作輥軋制不銹鋼板帶的使用性能要求,為實現(xiàn)MC3冷軋工作輥在惡劣復雜的工作條件下保持使用壽命的穩(wěn)定乃至升高提供理論依據(jù)。
[Abstract]:Nowadays, rolling process is involved in many material processing processes, and the performance of roll largely determines the product quality. As the key component of the rolling mill, the roll will be subjected to a variety of external stresses in operation, and the direction and strength of these forces are not regular, so the service life of the roll is limited. The life of roll mainly depends on the surface hardness of roll, the depth of effective hardened layer and the strength and toughness of roll. In this paper, the small specification MC3 cold rolling work roll is mainly used in rolling stainless steel strip, which should have many excellent mechanical properties, including hardness. Toughness, strength and surface hardness should reach HRC 60 to prevent roll failure during work. The whole quenching and heat treatment technology is commonly used in cold rolling work roll. If the roll wants to satisfy the above properties, the quenching and cooling process should be done by water quenching oil cooling process. However, the unstability of water quenched oil cooling process parameters of MC3 cold rolling work roll is greatly influenced by human being, resulting in the corresponding change of the structure and properties of the roll, and the damage caused by the pressure on the roll during the production. The end result is that rollers quickly fail to work properly, leading to shutdown in severe cases. In order to solve this problem, the water quenching process parameters of cold rolling work roll are studied in this paper. According to the characteristics of water-quenched oil cooling process of cold rolling work roll, SEM scanning electron microscope, metallographic microscope, Rockwell and Vickers hardness tester, impact tester and so on are used to test the microstructure and properties. Furthermore, various external and internal factors affecting roll service life are discussed, and the solutions are put forward. At the same time, it also analyzes how the water quenching time affects the properties of the material, and then improves the heat treatment process. The results show that the hardness gradient is steeper around the hardened layer and the metallographic structure changes obviously in the abnormal failure roll, and the hardness gradient of the normal failure roll is more gentle. The proportion of dispersed carbides in the material is proportional to the time of water quenching, as is the proportion of martensite formed during quenching and the depth of hardened layer. The result is an increase in steel hardness. However, the hardness gradient is not so large, and the curve is more moderate. With the increase of water quenching time, the impact property decreases gradually, and with the increase of surface distance, the impact toughness decreases gradually at the same position. After spheroidizing annealing at 870 鈩，

本文編號：1967407