提高冷轧带肋钢筋轧辊使用寿命的研究
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摘要
目前使用的冷轧带肋钢筋轧辊由于诸多原因，寿命很短，这严重制约了冷轧带肋钢筋的使用及生产厂家的经济效益。
为了解决冷轧带肋钢筋轧辊寿命短的问题，通过失效分析发现，轧辊失效多是工作面不耐磨引起的，为了提高轧辊耐磨性，在试验中选用高碳高合金钢Cr12MolⅤ，并且，考虑到生产成本，也尝试对高碳低合金钢9Cr2Mo采用化学热处理的工艺。
在试验中，通过改变Cr12MolⅤ的锻造工艺，采用高频、中频、盐浴、真空淬火、深冷处理等工艺处理试样，以及对试样实施渗氮、渗硼、硼氮共渗等化学热处理，通过做磨损试验、使用试验、X—射线衍射、金相分析、SEM扫描，研究了各种处理工艺对模具耐磨性及使用寿命的影响。
通过试验，得出如下结论：
1)对Cr12MolⅤ采用六面锻造+锻后余热淬火工艺，可以细化碳化物、奥氏体晶粒，促使碳化物均匀分布，可以提高耐磨性；
2)Cr12MolⅤ整体淬火后，采用液氮深冷处理，不但可以提高硬度，减少残余奥氏体量，而且可以减少残余应力，提高耐磨性；
3)Cr12MolⅤ真空淬火后，采用离子渗氮工艺处理，可使表面强化，又消除了淬火应力，耐磨性最好；
4)Cr12MolⅤ钢轧辊采用中频处理，不但淬硬层厚度增加，而且表面硬度的均匀性也提高，经过现场使用，可使其寿命达到80吨以上。
5)9Cr2Mo渗硼后，再采用氮气保护淬火工艺，渗硼层耐磨性与采用深冷处理的Cr12MolⅤ钢耐磨性相当，达到了轧制80吨钢筋的目标。
The process of enhancing wear resistance and prolonging the service life of cold roller with rib was studied in this paper.
For many factors, presently ,the service life of the cold roller is low, which serviously restricted the application of cold rolling reinforcing steel with rib and economic benefit of enterprise.
In order to solve the problem,by analyzing the damaged roller , the cause was that the working layer had poor wear resistance. In order to enhance wear resistance of the roller, high_carbon and high_alloy steel-Cr12MolV steel was adopted. For the sake of cost, high_carbon and low_alloy steel -9Cr2Mo steel was also adopted, and it was treated by thermochemical treatment.
In the experiment, common forging process of Cr12MolV steel was substituted with six_facets forging process. And high-frequency hardening, medium-frequency hardening, salt-bath hardening, vacuum-furance hardening, cryogenic treatment were adopted. By means of doing wear experiment , X-ray diffraction, metallographic examination, SEM scaning, effect of each treatment process on wear resistance and the service life of the cold roller with rib was studied.
By means of the experiment, the conclusions were summaried as following:
1) Cr12Mo1V steel was treated by adopting six-facets forging and ausforging, which made the coarse carbide broken and homogeneously distributed, and which made austenite grain refined. So the wear resistance was enhanced.
2) Cr12Mo1V steel was treated by bulk hardening and cryogenic treatment, which didn't only enhance hardness and decreased the amount of retained austenite, but also decreased residual stresses. So the wear resistance was enhanced.
3) Cr12Mo1V steel was treated by vacuum hardening and nitriding , which made surface hardening and decreased quenching stresses. So the wear resistance was enhanced.
4) Cr12MolV steel was treated by medium-frequency hardening, which didn't only enhance the effective depth of hardening, but also enhanced homogeneity of surface hardness. The roller treated by this process could produce eighty tons of reinforcing steel.
Our object was archieved.
5) 9Cr2Mo steel was treated by boronizing and protective atmosphere hardening, and wear resistance of boride layer was equivalent to wear resistance of Cr12MolV steel treated by bulk hardening and cryogenic treatment. The roller treated by this process can produce eighty tons of reinforcing steel. Our object was archieved.
为了解决冷轧带肋钢筋轧辊寿命短的问题，通过失效分析发现，轧辊失效多是工作面不耐磨引起的，为了提高轧辊耐磨性，在试验中选用高碳高合金钢Cr12MolⅤ，并且，考虑到生产成本，也尝试对高碳低合金钢9Cr2Mo采用化学热处理的工艺。
在试验中，通过改变Cr12MolⅤ的锻造工艺，采用高频、中频、盐浴、真空淬火、深冷处理等工艺处理试样，以及对试样实施渗氮、渗硼、硼氮共渗等化学热处理，通过做磨损试验、使用试验、X—射线衍射、金相分析、SEM扫描，研究了各种处理工艺对模具耐磨性及使用寿命的影响。
通过试验，得出如下结论：
1)对Cr12MolⅤ采用六面锻造+锻后余热淬火工艺，可以细化碳化物、奥氏体晶粒，促使碳化物均匀分布，可以提高耐磨性；
2)Cr12MolⅤ整体淬火后，采用液氮深冷处理，不但可以提高硬度，减少残余奥氏体量，而且可以减少残余应力，提高耐磨性；
3)Cr12MolⅤ真空淬火后，采用离子渗氮工艺处理，可使表面强化，又消除了淬火应力，耐磨性最好；
4)Cr12MolⅤ钢轧辊采用中频处理，不但淬硬层厚度增加，而且表面硬度的均匀性也提高，经过现场使用，可使其寿命达到80吨以上。
5)9Cr2Mo渗硼后，再采用氮气保护淬火工艺，渗硼层耐磨性与采用深冷处理的Cr12MolⅤ钢耐磨性相当，达到了轧制80吨钢筋的目标。
The process of enhancing wear resistance and prolonging the service life of cold roller with rib was studied in this paper.
For many factors, presently ,the service life of the cold roller is low, which serviously restricted the application of cold rolling reinforcing steel with rib and economic benefit of enterprise.
In order to solve the problem,by analyzing the damaged roller , the cause was that the working layer had poor wear resistance. In order to enhance wear resistance of the roller, high_carbon and high_alloy steel-Cr12MolV steel was adopted. For the sake of cost, high_carbon and low_alloy steel -9Cr2Mo steel was also adopted, and it was treated by thermochemical treatment.
In the experiment, common forging process of Cr12MolV steel was substituted with six_facets forging process. And high-frequency hardening, medium-frequency hardening, salt-bath hardening, vacuum-furance hardening, cryogenic treatment were adopted. By means of doing wear experiment , X-ray diffraction, metallographic examination, SEM scaning, effect of each treatment process on wear resistance and the service life of the cold roller with rib was studied.
By means of the experiment, the conclusions were summaried as following:
1) Cr12Mo1V steel was treated by adopting six-facets forging and ausforging, which made the coarse carbide broken and homogeneously distributed, and which made austenite grain refined. So the wear resistance was enhanced.
2) Cr12Mo1V steel was treated by bulk hardening and cryogenic treatment, which didn't only enhance hardness and decreased the amount of retained austenite, but also decreased residual stresses. So the wear resistance was enhanced.
3) Cr12Mo1V steel was treated by vacuum hardening and nitriding , which made surface hardening and decreased quenching stresses. So the wear resistance was enhanced.
4) Cr12MolV steel was treated by medium-frequency hardening, which didn't only enhance the effective depth of hardening, but also enhanced homogeneity of surface hardness. The roller treated by this process could produce eighty tons of reinforcing steel.
Our object was archieved.
5) 9Cr2Mo steel was treated by boronizing and protective atmosphere hardening, and wear resistance of boride layer was equivalent to wear resistance of Cr12MolV steel treated by bulk hardening and cryogenic treatment. The roller treated by this process can produce eighty tons of reinforcing steel. Our object was archieved.
引文
1 许发樾，实用模具设计与制造手册·机械工业出版社，2002年第一版
2 徐进 模具材料应用手册·机械工业出版社，2001年10月第一版
3 黄其华·提高Cr12MoV钢和9CrSi钢冷墩模寿命的热处理途径·金属热处理，1990(5)：34～37
4 姜祖赓·模具钢·冶金工业出版社，1988年第一版
5 蔡美良等·新编工模具钢金相热处理·1998年9月第一版，机械工业出版社
6 束德林·金属力学性能·机械工业出版社，1987年11月第一版，
7 竹内榮一·材料技术者(1)·热处理，1998(2)：90
8 李朝志·Cr12Mo1V钢锻热淬火显微组织形态的特殊性·中国机械工程，19996(5)：99～101
9 雷廷权·金属热处理工艺方法500种·机械工业出版社，1998年9月第一版
10 Richardson．R．C．D·The Wear of Metals by Relatively soft Abrasives·Wear, 1968(11)
11 揭晓华等·热处理工艺对Cr12MoV钢耐磨性能的影响·热加工工艺，1994(1)：32～34
12 高殿奎·复合凹凸模失效分析与工艺改进·金属热处理，2002，27(8)：55～57
13 Uhrenius. b. Hardenability Concepts with Applications to Steel, Ed.by.D.V.Doane and J. S. Kirkaldy, AIME, 1978(5)
14 TS—C6, 日特技报，1978-7-2
15 Dawes C· etal· Metals Technology, 1979(9): 345～353
16 C.K.Kwok.G.Thomas · Wear of Materials, 1983(2): 140～147
17 大和久重雄著·热处理108·机械技术出版社，1986
18 弘津真祯彦·碳钢马氏体回火过程中的结构变化[J]·热处理，1974(6)：323～329
19 T.P.Sweeney, Jr. Deep cryogenies, the great cold debate,Treating,1986(2):23～26
20 Rosenheinrich M ·Influence of Volume Fraction, Shape and Distributtion of the Austenite Phase on the Mechanical Properties of Steel X2CrNiMoN22[J]· Steel Res,1989,60(6): 274～277
21 尹延国等·深冷处理与工模具的耐磨性·金属热处理，1996(8)：27
22 尹熙武·D2钢的耐磨机理探讨·特钢技术，1999(1)：1
23 翟润华译·模具的深冷处理·模具工业，1988(12)：36～39
24 赵秀娟等·高碳合金钢的深冷处理研究·新技术新工艺，1997(1)：27～29
25 董俊译·工具钢的深冷处理·国外金属热处理，1997(2)：8～10
26 Moore k, Collins D N· Cryogenic treatment of three heat-heated tool steels key[J] · Engineering Materials,1993 (1993 (6): 47～54
27 余力林·Cr12Mov钢的深冷处理及其强化机制的研究·金属热处理[J]，1991(1)：24～27
28 Kohsuke TAGASHIRA· Role of Eta-carbide Precipitations in the Wear Resistance Improvements of Fe-12Cr-Mo-V-1.4C Tool Steel by Cryogenic Treatment ·ISIJ Intenational,Vol· 34(1994), No.2.pp.205-210
29 夏立芳·金属热处理工艺学·哈尔滨工业大学出版社，1985
30 劳动部培训司编·金属材料与热处理·中国劳动出版社，1990年第三版
31 宋维熙·金属学·冶金工业出版社·1989第二版
32 胡明娟等·钢铁化学热处理原理·上海交通大学出版社，1986年3月第一版
33 腾绩·铸锻造热处理，1986(11)：23～32
34 椿野晴繁·铁钢材料度强因子劣化因子·热处理，1999(5)：227
35 吴鲁周等·渗硼层的耐磨性和脆性·金属热处理，1983(6)：42
36 孙希太等·硼铁一氟硼酸钾一氧化铝粉末渗硼及其应用·金属热处理，1989(4)：25～29
37 大和久重雄·处理·熟处理，1999(1)：12
38 梁逵等·氮在硼氮复合渗中的作用·金属热处理，2001(1)：29～31
39 王志新等·硼氮共渗过程中碳原子活动规律研究·郑州轻工业学院学报，2001(1)：14～16
40 中国机械工程学会热处理专业学会《热处理手册》编委会编·热处理手册·机械工业出版社，1992年第二版，第四卷
41 第一机械部上海材料研究所编·工具钢金相图谱·机械工业出版社，1979年10月第一版
42 冶金部标准化研究所编·钢材标准高倍金相评级图·冶金工业出版，1980年第一版
2 徐进 模具材料应用手册·机械工业出版社，2001年10月第一版
3 黄其华·提高Cr12MoV钢和9CrSi钢冷墩模寿命的热处理途径·金属热处理，1990(5)：34～37
4 姜祖赓·模具钢·冶金工业出版社，1988年第一版
5 蔡美良等·新编工模具钢金相热处理·1998年9月第一版，机械工业出版社
6 束德林·金属力学性能·机械工业出版社，1987年11月第一版，
7 竹内榮一·材料技术者(1)·热处理，1998(2)：90
8 李朝志·Cr12Mo1V钢锻热淬火显微组织形态的特殊性·中国机械工程，19996(5)：99～101
9 雷廷权·金属热处理工艺方法500种·机械工业出版社，1998年9月第一版
10 Richardson．R．C．D·The Wear of Metals by Relatively soft Abrasives·Wear, 1968(11)
11 揭晓华等·热处理工艺对Cr12MoV钢耐磨性能的影响·热加工工艺，1994(1)：32～34
12 高殿奎·复合凹凸模失效分析与工艺改进·金属热处理，2002，27(8)：55～57
13 Uhrenius. b. Hardenability Concepts with Applications to Steel, Ed.by.D.V.Doane and J. S. Kirkaldy, AIME, 1978(5)
14 TS—C6, 日特技报，1978-7-2
15 Dawes C· etal· Metals Technology, 1979(9): 345～353
16 C.K.Kwok.G.Thomas · Wear of Materials, 1983(2): 140～147
17 大和久重雄著·热处理108·机械技术出版社，1986
18 弘津真祯彦·碳钢马氏体回火过程中的结构变化[J]·热处理，1974(6)：323～329
19 T.P.Sweeney, Jr. Deep cryogenies, the great cold debate,Treating,1986(2):23～26
20 Rosenheinrich M ·Influence of Volume Fraction, Shape and Distributtion of the Austenite Phase on the Mechanical Properties of Steel X2CrNiMoN22[J]· Steel Res,1989,60(6): 274～277
21 尹延国等·深冷处理与工模具的耐磨性·金属热处理，1996(8)：27
22 尹熙武·D2钢的耐磨机理探讨·特钢技术，1999(1)：1
23 翟润华译·模具的深冷处理·模具工业，1988(12)：36～39
24 赵秀娟等·高碳合金钢的深冷处理研究·新技术新工艺，1997(1)：27～29
25 董俊译·工具钢的深冷处理·国外金属热处理，1997(2)：8～10
26 Moore k, Collins D N· Cryogenic treatment of three heat-heated tool steels key[J] · Engineering Materials,1993 (1993 (6): 47～54
27 余力林·Cr12Mov钢的深冷处理及其强化机制的研究·金属热处理[J]，1991(1)：24～27
28 Kohsuke TAGASHIRA· Role of Eta-carbide Precipitations in the Wear Resistance Improvements of Fe-12Cr-Mo-V-1.4C Tool Steel by Cryogenic Treatment ·ISIJ Intenational,Vol· 34(1994), No.2.pp.205-210
29 夏立芳·金属热处理工艺学·哈尔滨工业大学出版社，1985
30 劳动部培训司编·金属材料与热处理·中国劳动出版社，1990年第三版
31 宋维熙·金属学·冶金工业出版社·1989第二版
32 胡明娟等·钢铁化学热处理原理·上海交通大学出版社，1986年3月第一版
33 腾绩·铸锻造热处理，1986(11)：23～32
34 椿野晴繁·铁钢材料度强因子劣化因子·热处理，1999(5)：227
35 吴鲁周等·渗硼层的耐磨性和脆性·金属热处理，1983(6)：42
36 孙希太等·硼铁一氟硼酸钾一氧化铝粉末渗硼及其应用·金属热处理，1989(4)：25～29
37 大和久重雄·处理·熟处理，1999(1)：12
38 梁逵等·氮在硼氮复合渗中的作用·金属热处理，2001(1)：29～31
39 王志新等·硼氮共渗过程中碳原子活动规律研究·郑州轻工业学院学报，2001(1)：14～16
40 中国机械工程学会热处理专业学会《热处理手册》编委会编·热处理手册·机械工业出版社，1992年第二版，第四卷
41 第一机械部上海材料研究所编·工具钢金相图谱·机械工业出版社，1979年10月第一版
42 冶金部标准化研究所编·钢材标准高倍金相评级图·冶金工业出版，1980年第一版