CN113588365A - 一种准确评估焊接用钢盘条拉拔加工性能的方法 - Google Patents
一种准确评估焊接用钢盘条拉拔加工性能的方法 Download PDFInfo
- Publication number
- CN113588365A CN113588365A CN202110844401.5A CN202110844401A CN113588365A CN 113588365 A CN113588365 A CN 113588365A CN 202110844401 A CN202110844401 A CN 202110844401A CN 113588365 A CN113588365 A CN 113588365A
- Authority
- CN
- China
- Prior art keywords
- wire rod
- martensite
- metallographic
- welding
- steel wire
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000000034 method Methods 0.000 title claims abstract description 24
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 22
- 239000010959 steel Substances 0.000 title claims abstract description 22
- 238000003466 welding Methods 0.000 title claims abstract description 22
- 238000012545 processing Methods 0.000 title claims abstract description 16
- 229910001563 bainite Inorganic materials 0.000 claims abstract description 30
- 229910000734 martensite Inorganic materials 0.000 claims abstract description 30
- 238000010622 cold drawing Methods 0.000 claims abstract description 14
- 230000003287 optical effect Effects 0.000 claims abstract description 9
- 238000005498 polishing Methods 0.000 claims abstract description 7
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims abstract description 6
- 239000010931 gold Substances 0.000 claims abstract description 6
- 229910052737 gold Inorganic materials 0.000 claims abstract description 6
- 238000005260 corrosion Methods 0.000 claims abstract description 3
- 230000007797 corrosion Effects 0.000 claims abstract description 3
- 238000005070 sampling Methods 0.000 claims description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 4
- 239000003518 caustics Substances 0.000 claims 1
- 238000012360 testing method Methods 0.000 abstract description 4
- 238000000227 grinding Methods 0.000 abstract 1
- 238000004519 manufacturing process Methods 0.000 description 5
- 239000002994 raw material Substances 0.000 description 4
- 239000000463 material Substances 0.000 description 3
- 229910001562 pearlite Inorganic materials 0.000 description 3
- 229910000859 α-Fe Inorganic materials 0.000 description 3
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 2
- 230000002159 abnormal effect Effects 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 229910017604 nitric acid Inorganic materials 0.000 description 2
- 230000035515 penetration Effects 0.000 description 2
- 229910000851 Alloy steel Inorganic materials 0.000 description 1
- 241001391944 Commicarpus scandens Species 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 238000000137 annealing Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000010587 phase diagram Methods 0.000 description 1
- 238000012797 qualification Methods 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/286—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q involving mechanical work, e.g. chopping, disintegrating, compacting, homogenising
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/32—Polishing; Etching
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/36—Embedding or analogous mounting of samples
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/84—Systems specially adapted for particular applications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N1/00—Sampling; Preparing specimens for investigation
- G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
- G01N1/286—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q involving mechanical work, e.g. chopping, disintegrating, compacting, homogenising
- G01N2001/2866—Grinding or homogeneising
Landscapes
- Physics & Mathematics (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Investigating And Analyzing Materials By Characteristic Methods (AREA)
- Heat Treatment Of Steel (AREA)
Abstract
本发明提供一种准确评估焊接用钢盘条拉拔加工性能的方法,所述方法为:在盘条代表性位置取金相样棒;将金相样棒横截面进行热镶嵌制成金相样品后,进行机械磨抛并腐蚀;把金相样品放在光学显微镜下观察,找出马氏体和/或贝氏体组织并拍摄照片;根据显微组织照片中马氏体贝氏体组织所占的比例大小准确判定盘条的拉拔性能。通过金相检验评估盘条组织中的马氏体/贝氏体严重程度来判定盘条的冷拉拔加工性能,比传统检验盘条拉伸性能的方法更为准确、可靠,本方法可用于钢厂产品出厂或金属制品厂购进原材料的验收标准,也可作为金属制品厂选择加工工艺的评判标准。
Description
技术领域
本发明涉及高速线材生产技术领域,具体为一种准确评估焊接用钢盘条拉拔加工性能的方法。
背景技术
焊丝材料如ER70S-6等一般由直径5.5mm的盘条经多道次冷拉拔加工至直径1.2mm甚至更细的细丝,因此要求盘条原料具有良好的冷拉拔加工性能。根据GB/T3429-2015《焊接用钢盘条》要求,一般每批取2个拉伸试样检测其拉伸力学性能。由于焊接用钢一般为低碳低合金钢,高线控轧控冷生产的线材交付状态其显微组织以铁素体和珠光体为主,实际测得的断面收缩率高达80%。然而在用户实际使用过程中,常出现碳素焊接用钢即便是断面收缩率80%的盘条,在细拉阶段也常因原料问题出现不可预料的断丝现象,而特种焊接用钢其断面收缩率虽然只有70%,却在整个拉拔过程中不发生断丝。由此可见,拉伸断面收缩率并不能准确地评价盘条的冷拉拔加工力学性能。
发明人通过对多年生产焊接用钢盘条及跟踪客户使用的经验、数据的分析和总结,发现造成焊丝材料细拉过程中断丝的原料问题主要是其显微组织中的马氏体/贝氏体异常组织。通过对盘条异常组织含量的检测可以准确评估其冷拉拔加工力学性能。
发明内容
本发明的目的在于提供一种准确评估焊接用钢盘条拉拔加工性能的方法,比传统测试拉伸力学性能的方法更加准确地评估盘条的冷拉拔加工性能,避免盲目投用盘条产生的断丝风险,提高生产效率。
为实现上述目的,本发明提供如下技术方案:准确评估焊接用钢盘条拉拔加工性能的方法为:所述方法依次包括如下步骤:
S1、在盘条代表性位置取金相样棒;
S2、将金相样棒横截面进行热镶嵌制成金相样品后,进行机械磨抛并腐蚀;
S3、把金相样品放在光学显微镜下观察,找出马氏体和/或贝氏体组织并拍摄照片;
S4、根据显微组织照片中马氏体贝氏体组织所占的比例大小准确判定盘条的拉拔性能。
优选的,步骤S1中盘条取样位置为一件盘卷剪净头尾不穿水的部分后,任取一圈盘条,在所取盘条上每间隔不大于30cm取一金相样棒,样棒长度3cm左右,一圈盘条取样数量不少于6个。
优选的,步骤S2中金相样品机械磨抛后腐蚀,腐蚀剂采用浓度为3-4%的硝酸酒精溶液。
优选的,步骤S3中所述光学显微镜放大倍数为500倍。
优选的,步骤S4中通过将显微组织照片和对照标准图谱对照进行判定,当马氏体小于1级且贝氏体小于2级时,冷拉拔性能较好,不易断丝。
优选的,所述对照标准图谱是根据重复步骤1-4统计的焊接用钢中马氏体/贝氏体组织含量与冷拉拔加工性能的关系,制定出的0-4级标准金相图谱。
本发明的有益效果是:
通过金相检验评估盘条组织中的马氏体/贝氏体严重程度来判定盘条的冷拉拔加工性能,比传统检验盘条拉伸性能的方法更为准确、可靠,本方法可用于钢厂产品出厂或金属制品厂购进原材料的验收标准,也可作为金属制品厂选择加工工艺的评判标准;发明人采用本专利方法,将马氏体/贝氏体级别作为产品拉拔性能合格与否的判定标准以来,共生产销售了50余万吨焊接用钢盘条,未发生一起因盘条问题导致的细拉断丝质量异议。
附图说明
图1为标准金相图谱0级样图;
图2为标准金相图谱1级样图;
图3为标准金相图谱2级样图;
图4为标准金相图谱3级样图;
图5为标准金相图谱4级样图;
图6为标准金相图谱5级样图;
图7为实施例2所检测盘条的金相图。
具体实施方式
下面对本发明实施例中的技术方案进行清楚、完整地描述,显然,所描述的实施例仅仅是本发明一部分实施例,而不是全部的实施例。基于本发明中的实施例,本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例,都属于本发明保护的范围。
实施例1
本实施例详细阐述准确评估焊接用钢盘条拉拔加工性能的方法,所述方法依次包括如下步骤:
S1、取高线生产的热轧盘条,头尾不穿水部分剪净后任取一圈,在取样线圈上每间隔30厘米取一金相样棒,取6个,确保取样位置覆盖线圈在斯太尔摩辊道上的中间和边部;
S2、将金相样棒横截面进行热镶嵌制成金相样品后进行机械磨抛,磨抛后采用浓度为3-4%的硝酸酒精溶液腐蚀;
S3、把金相样品放在光学显微镜下观察,找出马氏体和/或贝氏体组织最严重的的区域,并在光学显微镜放大500倍的条件下拍摄照片保存;
S4、重复步骤1-4,直至统计出马氏体/贝氏体含量与冷拉拔加工的对应关系,按马氏体和贝氏体含量的多少分为5级制作标准金相图谱,具体为:
0级:无马氏体或贝氏体组织,全部为铁素体和珠光体(见图1);
1级:马氏体和(或)贝氏体集中在金相样品心部,且数量≤10个;
2级:马氏体和(或)贝氏体集中的金相样品心部,且数量为10-20个;或者,马氏体和(或)贝氏体同时分布在金相样品的心部和边部;
3级:马氏体和(或)贝氏体集中的金相样品心部,且数量为20-30个;或者,马氏体和(或)贝氏体同时分布在金相样品的心部和边部,且数量均达到10个以上;
4级:组织以马氏体或贝氏体为主,仅有少量或无铁素体与珠光体。
当盘条马氏体小于1级且贝氏体小于2级时,冷拉拔性能较好,不易断丝。
实施例2
S1、取高线生产的热轧盘条,头尾不穿水部分剪净后任取一圈,在取样线圈上每间隔30厘米取一金相样棒,取6个,确保取样位置覆盖线圈在斯太尔摩辊道上的中间和边部;
S2、将金相样棒横截面进行热镶嵌制成金相样品后进行机械磨抛,磨抛后采用浓度为3-4%的硝酸酒精溶液腐蚀;
S3、把金相样品放在光学显微镜下观察,找出马氏体和/或贝氏体组织最严重的的区域,并在光学显微镜放大500倍的条件下拍摄照片保存;
S4、对照标准金相图谱,根据显微组织照片中马氏体贝氏体组织所占的比例大小判定某批次的盘条的拉拔性能为马氏体3级且贝氏体2级,冷拉拔加工性能较差,建议退火后再进行加工。
尽管已经示出和描述了本发明的实施例,对于本领域的普通技术人员而言,可以理解在不脱离本发明的原理和精神的情况下可以对这些实施例进行多种变化、修改、替换和变型,本发明的范围由所附权利要求及其等同物限定。
Claims (6)
1.一种准确评估焊接用钢盘条拉拔加工性能的方法,其特征在于,所述方法依次包括如下步骤:
S1、在盘条代表性位置取金相样棒;
S2、将金相样棒横截面进行热镶嵌制成金相样品后,进行机械磨抛并腐蚀;
S3、把金相样品放在光学显微镜下观察,找出马氏体和/或贝氏体组织并拍摄照片;
S4、根据显微组织照片中马氏体贝氏体组织所占的比例大小准确判定盘条的拉拔性能。
2.根据权利要求1所述的准确评估焊接用钢盘条拉拔加工性能的方法,其特征在于,步骤S1中盘条取样位置为一件盘卷剪净头尾不穿水的部分后,任取一圈盘条,在所取盘条上每间隔不大于30cm取一金相样棒,样棒长度3cm左右,一圈盘条取样数量不少于6个。
3.根据权利要求1所述的准确评估焊接用钢盘条拉拔加工性能的方法,其特征在于:步骤S2中金相样品机械磨抛后腐蚀,腐蚀剂采用浓度为3-4%的硝酸酒精溶液。
4.根据权利要求1所述的准确评估焊接用钢盘条拉拔加工性能的方法,其特征在于:步骤S3中所述光学显微镜放大倍数为500倍。
5.根据权利要求1所述的准确评估焊接用钢盘条拉拔加工性能的方法,其特征在于:步骤S4中通过将显微组织照片和对照标准图谱对照进行判定,当马氏体小于1级且贝氏体小于2级时,冷拉拔性能较好,不易断丝。
6.根据权利要求5所述的准确评估焊接用钢盘条拉拔加工性能的方法,其特征在于:所述对照标准图谱是根据重复步骤1-4统计的焊接用钢中马氏体/贝氏体组织含量与冷拉拔加工性能的关系,制定出的0-4级标准金相图谱。
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202110844401.5A CN113588365B (zh) | 2021-07-26 | 2021-07-26 | 一种准确评估焊接用钢盘条拉拔加工性能的方法 |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN202110844401.5A CN113588365B (zh) | 2021-07-26 | 2021-07-26 | 一种准确评估焊接用钢盘条拉拔加工性能的方法 |
Publications (2)
Publication Number | Publication Date |
---|---|
CN113588365A true CN113588365A (zh) | 2021-11-02 |
CN113588365B CN113588365B (zh) | 2024-03-29 |
Family
ID=78250140
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN202110844401.5A Active CN113588365B (zh) | 2021-07-26 | 2021-07-26 | 一种准确评估焊接用钢盘条拉拔加工性能的方法 |
Country Status (1)
Country | Link |
---|---|
CN (1) | CN113588365B (zh) |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005076078A (ja) * | 2003-08-29 | 2005-03-24 | Kobe Steel Ltd | 加工性に優れた高張力鋼板及びその製造方法 |
CN103411815A (zh) * | 2013-07-31 | 2013-11-27 | 攀钢集团攀枝花钢铁研究院有限公司 | 测定热轧双相钢中马氏体含量的方法 |
US20150050519A1 (en) * | 2012-01-13 | 2015-02-19 | Nippon Steel & Sumitomo Metal Corporation | Hot stamped steel and method for producing the same |
US20150111064A1 (en) * | 2012-03-27 | 2015-04-23 | Kabushiki Kaisha Kobe Seiko Sho(Kobe Steel, Ltd.) | High-strength hot-dip galvanized steel sheet and high-strength alloyed hot-dip galvanized steel sheet having excellent bending workability and minimal strength difference between center part and end parts in sheet width direction, and method for manufacturing same |
CN109540635A (zh) * | 2018-11-22 | 2019-03-29 | 大唐东北电力试验研究院有限公司 | 一种12Cr1MoV钢严重球化和正常金相组织的鉴别方法 |
CN111289338A (zh) * | 2020-03-31 | 2020-06-16 | 马鞍山钢铁股份有限公司 | 一种用于中高碳钢贝氏体深度测量的试验方法 |
JP2020186446A (ja) * | 2019-05-16 | 2020-11-19 | 日本製鉄株式会社 | 線材及び鋼線 |
CN112326296A (zh) * | 2020-10-20 | 2021-02-05 | 柳州钢铁股份有限公司 | 一种适用于分析金相组织与Agt性能关系的取样方法及系统 |
-
2021
- 2021-07-26 CN CN202110844401.5A patent/CN113588365B/zh active Active
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2005076078A (ja) * | 2003-08-29 | 2005-03-24 | Kobe Steel Ltd | 加工性に優れた高張力鋼板及びその製造方法 |
US20150050519A1 (en) * | 2012-01-13 | 2015-02-19 | Nippon Steel & Sumitomo Metal Corporation | Hot stamped steel and method for producing the same |
US20150111064A1 (en) * | 2012-03-27 | 2015-04-23 | Kabushiki Kaisha Kobe Seiko Sho(Kobe Steel, Ltd.) | High-strength hot-dip galvanized steel sheet and high-strength alloyed hot-dip galvanized steel sheet having excellent bending workability and minimal strength difference between center part and end parts in sheet width direction, and method for manufacturing same |
CN103411815A (zh) * | 2013-07-31 | 2013-11-27 | 攀钢集团攀枝花钢铁研究院有限公司 | 测定热轧双相钢中马氏体含量的方法 |
CN109540635A (zh) * | 2018-11-22 | 2019-03-29 | 大唐东北电力试验研究院有限公司 | 一种12Cr1MoV钢严重球化和正常金相组织的鉴别方法 |
JP2020186446A (ja) * | 2019-05-16 | 2020-11-19 | 日本製鉄株式会社 | 線材及び鋼線 |
CN111289338A (zh) * | 2020-03-31 | 2020-06-16 | 马鞍山钢铁股份有限公司 | 一种用于中高碳钢贝氏体深度测量的试验方法 |
CN112326296A (zh) * | 2020-10-20 | 2021-02-05 | 柳州钢铁股份有限公司 | 一种适用于分析金相组织与Agt性能关系的取样方法及系统 |
Non-Patent Citations (3)
Title |
---|
沈奎等: "洁净度和控轧控冷工艺对SCM435热轧盘条塑性指标的影响", 特殊钢, vol. 33, no. 05, pages 61 - 64 * |
田庆荣 等: "非金属夹杂物和金相组织对板材伸长率的影响", 物理测试, vol. 29, no. 04, pages 23 - 26 * |
高志平等: "焊接用盘条拉拔断裂原因分析", 金属制品, vol. 31, no. 2, pages 28 - 31 * |
Also Published As
Publication number | Publication date |
---|---|
CN113588365B (zh) | 2024-03-29 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN101903553B (zh) | 耐腐蚀性和加工性优异的高纯度铁素体系不锈钢及其制造方法 | |
CN102066599A (zh) | 高强度极细钢线及其制造方法 | |
EP2902521B1 (en) | Super non-magnetic soft stainless steel wire material having excellent cold workability and corrosion resistance, method for manufacturing same, steel wire, steel wire coil, and method for manufacturing same | |
RU2682728C2 (ru) | Высокопрочная, толстостенная, бесшовная труба из нержавеющей стали и способ изготовления такой трубы | |
US20160002755A1 (en) | High-strength steel wire material exhibiting excellent cold-drawing properties, and high-strength steel wire | |
CN102791898A (zh) | 耐延迟断裂特性优异的高强度钢材和高强度螺栓及其制造方法 | |
US20190024222A1 (en) | Steel wire for non-heat treated machine part and non-heat treated machine part | |
JP2013521132A (ja) | ステンレス鋼製品を製造する方法 | |
Karsch et al. | Influence of hydrogen content and microstructure on the fatigue behaviour of steel SAE 52100 in the VHCF regime | |
EP3988678A1 (en) | Wire rod | |
Alexandreanu et al. | The role of stress in the efficacy of coincident site lattice boundaries in improving creep and stress corrosion cracking | |
CN100510140C (zh) | 油井用马氏体系不锈钢管 | |
EP4108797A1 (en) | High-strength stainless steel seamless pipe for oil well, and method for producing same | |
EP3327161B1 (en) | High-strength pc steel wire | |
CN113588365A (zh) | 一种准确评估焊接用钢盘条拉拔加工性能的方法 | |
EP3327162A1 (en) | High-strength pc steel wire | |
Franceschini et al. | An assessment of cleanliness techniques for low alloyed steel grades | |
JP2000329726A (ja) | 鋼材の水素脆化感受性の評価方法 | |
EP4324945A1 (en) | Drawn wire material, and method for producing drawn wire material | |
CN115356200A (zh) | 基于断裂试样的油井管抗硫化氢应力腐蚀敏感性测试方法 | |
JP7469642B2 (ja) | 高強度鋼線 | |
JP7295412B2 (ja) | 金属材料の評価方法 | |
Latypova et al. | Hydrogen-induced cracking of 500 HBW steels studied using a novel tuning-fork test with integrated loadcell system | |
JP2004002988A (ja) | 曲げ加工性に優れたりん青銅条 | |
CN115201097A (zh) | 一种不锈钢丝绳耐腐蚀性试验方法 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PB01 | Publication | ||
PB01 | Publication | ||
SE01 | Entry into force of request for substantive examination | ||
SE01 | Entry into force of request for substantive examination | ||
GR01 | Patent grant | ||
GR01 | Patent grant |