CN113714747A - 一种制备轴类零件表面涂层的感应熔敷工艺流程 - Google Patents

一种制备轴类零件表面涂层的感应熔敷工艺流程 Download PDF

Info

Publication number
CN113714747A
CN113714747A CN202111096685.0A CN202111096685A CN113714747A CN 113714747 A CN113714747 A CN 113714747A CN 202111096685 A CN202111096685 A CN 202111096685A CN 113714747 A CN113714747 A CN 113714747A
Authority
CN
China
Prior art keywords
coating
shaft part
drying
preparing
shaft
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.)
Pending
Application number
CN202111096685.0A
Other languages
English (en)
Inventor
胡雪
陈育龙
张立新
张胜利
史雪宾
郑雄飞
买春亮
董峰
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shihezi University
Original Assignee
Shihezi University
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Shihezi University filed Critical Shihezi University
Priority to CN202111096685.0A priority Critical patent/CN113714747A/zh
Publication of CN113714747A publication Critical patent/CN113714747A/zh
Pending legal-status Critical Current

Links

Images

Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B23MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23PMETAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS
    • B23P15/00Making specific metal objects by operations not covered by a single other subclass or a group in this subclass
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B05SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05DPROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D3/00Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials
    • B05D3/002Pretreatement
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B05SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05DPROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D3/00Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials
    • B05D3/007After-treatment
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B05SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05DPROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D3/00Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials
    • B05D3/02Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials by baking
    • B05D3/0254After-treatment
    • B05D3/0272After-treatment with ovens
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B05SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05DPROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D3/00Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials
    • B05D3/02Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials by baking
    • B05D3/0254After-treatment
    • B05D3/0281After-treatment with induction heating
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B05SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05DPROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D3/00Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials
    • B05D3/04Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials by exposure to gases
    • B05D3/0406Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials by exposure to gases the gas being air
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B05SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05DPROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D3/00Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials
    • B05D3/04Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials by exposure to gases
    • B05D3/0406Pretreatment of surfaces to which liquids or other fluent materials are to be applied; After-treatment of applied coatings, e.g. intermediate treating of an applied coating preparatory to subsequent applications of liquids or other fluent materials by exposure to gases the gas being air
    • B05D3/0426Cooling with air
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B05SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05DPROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
    • B05D7/00Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials
    • B05D7/24Processes, other than flocking, specially adapted for applying liquids or other fluent materials to particular surfaces or for applying particular liquids or other fluent materials for applying particular liquids or other fluent materials
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B23MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • B23KSOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
    • B23K13/00Welding by high-frequency current heating
    • B23K13/01Welding by high-frequency current heating by induction heating

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Wood Science & Technology (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)

Abstract

本发明涉及一种制备轴类零件表面涂层的感应熔敷工艺流程,包括以下步骤:S1:施工前期准备,检查轴类零件以及各项原材料;S2:轴类零件表面喷砂处理,选用石榴石磨料;S3:轴类零件表面除油处理,置于有机溶剂中除油;S4:轴类零件表面吹干处理,使用吹风机吹干;S5:涂层制备,涂敷材料以及外部套筒的制备:S6:涂层涂敷于轴类零件表面;S7:烘干,去除未蒸发的水分;S8高频感应熔敷,设置高频感应熔敷工艺参数,进行感应熔敷;S9:冷却,采用水冷冷却;S10:检查、入库,检查涂层是否符合要求,分类放置于仓库中。使用此工艺流程制备的轴类零件涂层,成型规则,厚度均匀,可以有效提升零件的机械性能和使用寿命。

Description

一种制备轴类零件表面涂层的感应熔敷工艺流程
技术领域
本发明涉及感应熔敷领域,尤其涉及一种制备轴类零件表面涂层的感应熔敷工艺流程。
背景技术
为实现降低能耗的目标,掌握机械装备关键零部件再制造技术,是实现国家可持续发展战略的基础所在,磨损、疲劳、腐蚀等现象是工程材料失效、破坏的主要原因,而轴类零件在工程材料的应用中最为广泛,也是最为关键的零件之一。轴类零件的失效、破坏多发生在表面或由表面开始,对其表面进行修复,一定程度上可有效缓解磨损、疲劳、腐蚀等现象的发生。
发明内容
本发明的目的在于提供一种制备轴类零件表面涂层的感应熔敷工艺流程,已解决背景技术中提出的问题。
为了解决上述技术问题,本发明提供了如下技术方案:一种制备轴类零件表面涂层的感应熔敷工艺流程,包括以下步骤:
S1:施工前期准备,清除轴类零件表面杂质,同时对轴类零件以及各项原材料进行全方位的检查,确保符合且满足感应熔敷使用要求;
S2:轴类零件表面喷砂处理,选用石榴石磨料进行喷砂处理,处理完毕后去除表面产生的各种杂质;
S3:轴类零件表面除油处理,将喷砂处理好的轴类零件置于石油溶剂、松节油、二甲苯等有机溶剂中清洗,去除表面油污,有利于轴类零件表面与涂层的结合;
S4:轴类零件表面吹干处理,使用吹风机,使轴类零件表面处于干燥状态;
S5:涂层制备,按照一定的比例进行涂敷材料以及外部套筒的制备;
S6:涂层涂敷于轴类零件表面,将制备好的涂敷材料涂敷于轴类零件表面,外部套筒覆盖于涂敷材料外部,外部套筒起到稳定包裹涂敷材料的作用;
S7:烘干:将涂敷好的轴类零件,在空气中放置一天,然后置于烘干箱中进行烘干;
S8:高频感应熔敷,连接高频感应熔敷设备,设置工艺参数,进行高频感应熔敷;
S9:冷却,采用水冷冷却方式,可以获得脆硬性更好的涂层;
S10:检查、入库,检查涂层是否符合要求,分类放置于仓库中。
所述的一种制备轴类零件表面涂层的感应熔敷工艺流程,其特征是在所述S5涂层制备中,涂敷材料按照Ni60合金粉末与生石灰粉末40:1的比例,同时加入泡花碱水溶液,按照1克生石灰粉末2-3ml泡花碱水溶液比例加入,外部套筒按照62.5%黏土37.5%面粉比例制备。
通过上述技术方案,能够得到较好的熔敷层成形质量,经感应熔敷形成的涂层表面厚度均匀,成形规则,无较大气孔、裂纹、杂质等现象的发生。
所述的一种制备轴类零件表面涂层的感应熔敷工艺流程,其特征是在所述S7烘干中,将涂敷好的轴类零件在空气中放置一天,然后将其放入烘干箱中,设置烘干温度为199-204℃,此温度略高于涂敷材料居里温度,烘干时间2-2.5h,将烘干箱中的轴类零件立即置于感应熔敷装置中加热。
通过上述技术方案,可以去除未蒸发的水分,有利于涂层的加热,同时保持工件恒温且略高于涂敷材料居里温度,进入加热熔涂状态,更有利于热量由基体表面向涂层的传导,烘干过程中,随着温度的升高,粉末颗粒充分接触,之间的空隙减少,涂层电阻率降低,更有利于电磁能在涂层上的集中。
所述的一种制备轴类零件表面涂层的感应熔敷工艺流程,其特征是在所述S8高频感应熔敷中,设置高频感应熔敷装置工艺参数为:功率40-42KW,转速14-16r/min,加热线圈内径40mm。
通过上述技术方案,能够得到较好的熔覆层成形质量,可以提高工件机械性能并延长其使用寿命。
附图说明
图1为本发明的流程简图。
具体实施方式
下面将结合本发明实施例中的附图,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的一部分实施例,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。
如图1所示,一种制备轴类零件表面涂层的感应熔敷工艺流程,包括以下步骤:
S1:施工前期准备,清除轴类零件表面杂质,同时对轴类零件以及各项原材料进行全方位的检查,确保符合且满足感应熔敷使用要求;
S2:轴类零件表面喷砂处理,选用石榴石磨料进行喷砂处理,处理完毕后去除表面产生的各种杂质;
S3:轴类零件表面除油处理,将喷砂处理好的轴类零件置于石油溶剂、松节油、二甲苯等有机溶剂中清洗,去除表面油污,有利于轴类零件表面与涂层的结合;
S4:轴类零件表面吹干处理,使用吹风机,使轴类零件表面处于干燥状态;
S5:涂层制备,按照一定的比例进行涂敷材料以及外部套筒的制备;
S6:涂层涂敷于轴类零件表面,将制备好的涂敷材料涂敷于轴类零件表面,外部套筒覆盖于涂敷材料外部,外部套筒起到稳定包裹涂敷材料的作用;
S7:烘干:将涂敷好的轴类零件,在空气中放置一天,然后置于烘干箱中进行烘干;
S8:高频感应熔敷,连接高频感应熔敷设备,设置工艺参数,进行高频感应熔敷;
S9:冷却,采用水冷冷却方式,可以获得脆硬性更好的涂层;
S10:检查、入库,检查涂层是否符合要求,分类放置于仓库中。
通过上述技术方案。
所述的一种制备轴类零件表面涂层的感应熔敷工艺流程,其特征是在所述S5涂层制备中,涂敷材料按照Ni60合金粉末与生石灰粉末40:1的比例,同时加入泡花碱水溶液,按照1克生石灰粉末2-3ml泡花碱水溶液比例加入,外部套筒按照62.5%黏土37.5%面粉比例制备。
通过上述技术方案,能够得到较好的熔敷层成形质量,经感应熔敷形成的涂层表面厚度均匀,成形规则,无较大气孔、裂纹、杂质等现象的发生。
所述的一种制备轴类零件表面涂层的感应熔敷工艺流程,其特征是在所述S7烘干中,将涂敷好的轴类零件在空气中放置一天,然后将其放入烘干箱中,设置烘干温度为199-204℃,此温度略高于涂敷材料居里温度,烘干时间2-2.5h,将烘干箱中的轴类零件立即置于感应熔敷装置中加热。
通过上述技术方案,可以去除未蒸发的水分,有利于涂层的加热,同时保持工件恒温且略高于涂敷材料居里温度,进入加热熔涂状态,更有利于热量由基体表面向涂层的传导,烘干过程中,随着温度的升高,粉末颗粒充分接触,之间的空隙减少,涂层电阻率降低,更有利于电磁能在涂层上的集中。
所述的一种制备轴类零件表面涂层的感应熔敷工艺流程,其特征是在所述S8高频感应熔敷中,设置高频感应熔敷装置工艺参数为:功率40-42KW,转速14-16r/min,加热线圈内径40mm。
通过上述技术方案,能够得到较好的熔覆层成形质量,可以提高工件机械性能并延长其使用寿命。

Claims (4)

1.一种制备轴类零件表面涂层的感应熔敷工艺流程,其特征在于:包括以下步骤:
S1:施工前期准备,清除轴类零件表面杂质,同时对轴类零件以及各项原材料进行全方位的检查,确保符合且满足感应熔敷使用要求;
S2:轴类零件表面喷砂处理,选用石榴石磨料进行喷砂处理,处理完毕后去除表面产生的各种杂质;
S3:轴类零件表面除油处理,将喷砂处理好的轴类零件置于石油溶剂、松节油、二甲苯等有机溶剂中清洗,去除表面油污,有利于轴类零件表面与涂层的结合;
S4:轴类零件表面吹干处理,使用吹风机,使轴类零件表面处于干燥状态;
S5:涂层制备,按照一定的比例进行涂敷材料以及外部套筒的制备;
S6:涂层涂敷于轴类零件表面,将制备好的涂敷材料涂敷于轴类零件表面,外部套筒覆盖于涂敷材料外部,外部套筒起到稳定包裹涂敷材料的作用;
S7:烘干:将涂敷好的轴类零件,在空气中放置一天,然后置于烘干箱中进行烘干;
S8:高频感应熔敷,连接高频感应熔敷设备,设置工艺参数,进行高频感应熔敷;
S9:冷却,采用水冷冷却方式,可以获得脆硬性更好的涂层;
S10:检查、入库,检查涂层是否符合要求,分类放置于仓库中。
2.根据权利要求1所述的一种制备轴类零件表面涂层的感应熔敷工艺流程,其特征在于:在所述S5涂层制备中,涂敷材料按照Ni60合金粉末与生石灰粉末40:1的比例,同时加入泡花碱水溶液,按照1克生石灰粉末2-3ml泡花碱水溶液比例加入,外部套筒按照62.5%黏土37.5%面粉比例制备。
3.根据权利要求1所述的一种制备轴类零件表面涂层的感应熔敷工艺流程,其特征在于:在所述S7烘干中,将涂敷好的轴类零件在空气中放置一天,然后将其放入烘干箱中,设置烘干温度为199-204℃,此温度略高于涂敷材料居里温度,烘干时间2-2.5h,随即将烘干箱中的轴类零件立即置于感应熔敷装置中加热。
4.根据权利要求1所述的一种制备轴类零件表面涂层的感应熔敷工艺流程,其特征在于:在所述S8高频感应熔敷中,设置高频感应熔敷装置工艺参数为:功率40-42KW,转速14-16r/min,加热线圈内径40mm。
CN202111096685.0A 2021-09-18 2021-09-18 一种制备轴类零件表面涂层的感应熔敷工艺流程 Pending CN113714747A (zh)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202111096685.0A CN113714747A (zh) 2021-09-18 2021-09-18 一种制备轴类零件表面涂层的感应熔敷工艺流程

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202111096685.0A CN113714747A (zh) 2021-09-18 2021-09-18 一种制备轴类零件表面涂层的感应熔敷工艺流程

Publications (1)

Publication Number Publication Date
CN113714747A true CN113714747A (zh) 2021-11-30

Family

ID=78684251

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202111096685.0A Pending CN113714747A (zh) 2021-09-18 2021-09-18 一种制备轴类零件表面涂层的感应熔敷工艺流程

Country Status (1)

Country Link
CN (1) CN113714747A (zh)

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2310810A1 (fr) * 1975-05-12 1976-12-10 Armco Steel Corp Procede pour former un revetement en matiere plastique sur un element long tel qu'un tube ou un fil metallique
US4244985A (en) * 1976-04-22 1981-01-13 Armco Inc. Method of curing thermosetting plastic powder coatings on elongated metallic members
CN1891860A (zh) * 2005-09-06 2007-01-10 中国矿业大学(北京) 一种零件表面熔覆层工艺方法
CN103042338A (zh) * 2011-10-12 2013-04-17 河北农业大学 一种基于零件再制造修复的反应氮弧熔覆耐磨涂层制备工艺
CN104988495A (zh) * 2015-06-29 2015-10-21 中国人民解放军装甲兵工程学院 一种套筒类零件内壁感应熔覆再制造方法
CN106676516A (zh) * 2016-11-18 2017-05-17 无锡明盛纺织机械有限公司 一种耐磨蚀抽油杆的制备方法
CN109136917A (zh) * 2018-09-18 2019-01-04 大连海事大学 一种提高灰铸铁耐磨性能的感应熔覆涂层制备方法
CN112877638A (zh) * 2021-03-10 2021-06-01 石河子大学 一种高速电弧喷涂涂层的制备工艺流程

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2310810A1 (fr) * 1975-05-12 1976-12-10 Armco Steel Corp Procede pour former un revetement en matiere plastique sur un element long tel qu'un tube ou un fil metallique
US4244985A (en) * 1976-04-22 1981-01-13 Armco Inc. Method of curing thermosetting plastic powder coatings on elongated metallic members
CN1891860A (zh) * 2005-09-06 2007-01-10 中国矿业大学(北京) 一种零件表面熔覆层工艺方法
CN103042338A (zh) * 2011-10-12 2013-04-17 河北农业大学 一种基于零件再制造修复的反应氮弧熔覆耐磨涂层制备工艺
CN104988495A (zh) * 2015-06-29 2015-10-21 中国人民解放军装甲兵工程学院 一种套筒类零件内壁感应熔覆再制造方法
CN106676516A (zh) * 2016-11-18 2017-05-17 无锡明盛纺织机械有限公司 一种耐磨蚀抽油杆的制备方法
CN109136917A (zh) * 2018-09-18 2019-01-04 大连海事大学 一种提高灰铸铁耐磨性能的感应熔覆涂层制备方法
CN112877638A (zh) * 2021-03-10 2021-06-01 石河子大学 一种高速电弧喷涂涂层的制备工艺流程

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
张臣: "高频感应熔覆层质量控制工艺研究", 《中国优秀硕士学位论文全文数据库工程科技Ⅰ辑》 *

Similar Documents

Publication Publication Date Title
CN106853508B (zh) 一种预防陶瓷型壳开裂的方法
CN103939937A (zh) 一种锅炉衬里材料的快速修补方法
CN105399453A (zh) 一种LaB6/Si-Mo梯度高温抗氧化涂层的制备方法
CN108587261B (zh) 一种新型的风机部件环保无机防腐蚀涂层及喷涂方法
CN113714747A (zh) 一种制备轴类零件表面涂层的感应熔敷工艺流程
CN103993316A (zh) 一种搪瓷传热元件及其涂搪方法
CN107805809A (zh) 一种汽车模具表面涂膜修复工艺
CN102211080A (zh) 钢结构表面的复合涂层防腐方法
RU2714190C1 (ru) Устойчивое к высоким температурам покрытие на водной основе, препятствующее связыванию титан-сталь, и его применение
CN103433686A (zh) 缸筒修复工艺
CN107915499B (zh) 一种C/SiC陶瓷基复合材料的修复方法
CN111575630B (zh) 一种基于等离子热喷技术的混凝土表面防护处理方法
CN103922811A (zh) 一种电瓷瓷件的修复方法
CN103952694A (zh) 激光修复搪玻璃设备的方法
CN105624711A (zh) 家电用金属板材脱脂工艺
CN107523782A (zh) 钼基合金表面抗氧化涂层及其制备方法
CN104630764A (zh) 一种钢件表明氧化工艺
CN104388922A (zh) 一种钢件烤蓝方法
CN102912286B (zh) 铝及铝合金液体氮化方法
CN105063616B (zh) 一种基于电子束环形枪熔覆棒料圆柱面的改性方法
CN111041182A (zh) 一种链条加工工艺方法
CN111378354A (zh) 一种耐高温防腐蚀防结垢粉末涂料及其施工方法
CN104152841A (zh) 一种碳套辊辊芯的表面处理工艺
CN104401975A (zh) 一种环保气刨炭棒及其制备方法
CN109608232B (zh) 一种内导式液压油缸表面陶瓷层修复方法

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
WD01 Invention patent application deemed withdrawn after publication

Application publication date: 20211130

WD01 Invention patent application deemed withdrawn after publication