CN117051225A - 一种形状不规则对称薄壁垫片淬火变形控制的工艺方法 - Google Patents
一种形状不规则对称薄壁垫片淬火变形控制的工艺方法 Download PDFInfo
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Abstract
本发明属于金属热处理技术领域,公开了一种形状不规则对称精密薄壁垫片淬火变形精确控制的工艺方法。利用:薄壁垫片“合二为一”两侧端面同步渗碳、淬回火,提高组件刚度及淬火冷却特性,然后线切割,“一分为二”,确保压模淬火变形控制精度;固体传递压力的原理,将薄壁垫片串联放置于工装心轴之上,进行压淬,提高生产效能。一次压淬多片增厚垫片时,给出了压模淬火心轴外径尺寸及增厚垫片的内径尺寸;压模淬火工装在工作前,需利用淬火流油进行预热。
Description
技术领域
本发明属于金属热处理技术领域,尤其涉及一种形状不规则对称薄壁垫片淬火变形控制的工艺方法。
背景技术
航空用精密薄壁垫片,外侧形状不规则对称,通常内径≥50mm、轴向厚度≤5mm、径向宽度≤30mm,单侧端面需要渗碳、淬回火进行表面强化,为保证垫片耐磨特性,薄壁垫片上下两侧平行端面渗碳、淬回火后的平面度≤0.10mm。
该类零件受结构设计限制,刚性弱,渗碳、淬火过程中均易产生翘曲变形,因回火温度≤200℃,无法通过回火阶段采取热校形的方式,改善薄壁垫片上下两侧平行端面的平面度。
由于零件轴向厚度过薄,形状呈不规则对称,且一侧端面渗碳、一侧端面未渗碳,零件不同部位淬火变形差异性极大。为提高此类零件淬火变形控制能力,工程技术人员通常采用压模淬火,但淬火变形控制效果差,压模淬火后,薄壁垫片出现回弹,上下两侧平行端面普遍平面度≥0.20mm,工序间产品合格率≤30%。
目前尚无相关文献报道大幅提升航空精密薄壁垫片淬火变形控制能力的相关报道。
发明内容
本发明的目的是:提供一种形状不规则对称精密薄壁垫片淬火变形精确控制的工艺方法,大幅提升航空精密薄壁垫片淬火变形控制能力,解决此类产品热处理工序间合格率过低问题,并提高生产效能。
本发明采用如下技术方案予以实现:
本发明提供一种形状不规则对称薄壁垫片淬火变形控制的工艺方法,所述方法包括:
S1,将两片薄壁垫片合二为一,并补偿线切割刀口和磨削修正余量;
S2,从而将两片薄壁垫片加工成组合垫片,对所述组合垫片两侧端面同步进行渗碳;
S3,对多个组合垫片进行压模淬火;
S4,将组合垫片一分为二,切割为两片薄壁垫片,转入机加工序,进行磨削。
进一步的,
S1中,补偿补偿线切割刀口和磨削修正余量为(0~2)mm。
进一步的,
S3中,对多个组合垫片进行压模淬火时,压模淬火工装的尺寸根据待压淬的薄壁垫片的个数进行设计,且多个薄壁垫片串联放置在压模淬火工装的淬火芯轴上。
进一步的,
所述淬火芯轴串装轴向高度大于(n-1)个薄壁垫片厚度,且小于n个薄壁垫片厚度,n为待压淬的薄壁垫片的总个数。
进一步的,
S3中,对多个组合垫片进行压模淬火时,下模工装的芯轴尺寸按照薄壁垫片内径淬火后要求的实际尺寸加工制造。
进一步的,
所述组合垫片的内径尺寸为下模工装的芯轴直径的1.001~1.01倍。
进一步的,
S3中,使用压模淬火工装进行压模淬火时,需通过淬火压床淬火流油对压模淬火工装进行预热。
进一步的,
在S3之后,且在S4之前,所述方法还包括:
对组合垫片进行渗碳淬火之后,还需要进行冰冷及回火处理。
本发明一种形状不规则对称精密薄壁垫片淬火变形精确控制的工艺方法,通过改善局部渗碳零件淬火冷却特性、增加组件刚度,将2片薄壁垫片“合二为一”,两侧同步渗碳后,进行淬火,再使用线切割“一分为二”,提高了航空精密薄壁垫片的淬火变形控制精度;同时,合理的开展压模淬火工装优化设计,并利用固体传递压力的原理,将淬火保温结束后的多片薄壁垫片串联放入淬火心轴,进行压模淬火,解决了原有淬火压床一次只能压淬一片薄壁垫片的技术难题,提升了淬火压床的使用效能。
附图说明
图1为本发明实施例提供的薄壁垫片的结构示意图;
图2为本发明实施例提供的压模淬火下模淬火工装结构示意图;
图3为本发明实施例提供的下模工装顶部摞放垫片的支口俯视图。
具体实施方式
下面结合附图对本发明技术方案进行详细说明。
本发明提供一种形状不规则对称薄壁垫片淬火变形控制的工艺方法,利用①薄壁垫片“合二为一”两侧端面同步渗碳、淬回火,提高组件刚度及淬火冷却特性,然后线切割,“一分为二”,确保压模淬火变形控制精度;②固体传递压力的原理,将薄壁垫片串联放置于工装心轴之上,进行压淬,提高生产效能。
首先调整机加工艺路线,转入到热处理工序的薄壁垫片厚度增厚1倍,然后增加(0~2.0)mm线切割“刀口”及磨削修正余量。
垫片增厚后,上下两侧端面同步按照原有工艺渗碳、淬火、冰冷、回火。
采用线切割,将热处理后的增厚垫片“一分为二”,切割成2片薄壁垫片,转入机加工序,进行磨削。
为提升生产效能,增厚垫片在淬火阶段,对原有压模淬火工装进行优化设计,根据垫片材质淬透性,适当增加一次压淬垫片的数量,提高生产效能。
压模淬火工装(如图2所示)的尺寸根据压模淬火待压淬的薄壁垫片个数进行设计,多片垫片串联放置到淬火心轴之后,确保(n-1)个垫片高度<淬火心轴串装轴向高度<n个垫片高度。
下模工装(如图3所示)心轴按照垫片内径淬火后要求的实际尺寸加工制造。
考虑到增厚垫片淬火后收缩、抱紧工装心轴,为便于取出垫片,增厚垫片的内径尺寸=下模工装心轴直径×(1.001~1.01)。
使用压模淬火时,淬火压模需通过淬火压床淬火流油进行预热。
实施例一
16Cr3NiWMoVNbE材料加工制造的薄壁垫片,热处理工序间内径φ68.5mm,轴向厚度4mm,径向宽度13mm,外侧形状不规则对称,垫片一侧端面渗碳后,采取压模淬火“校平”,垫片压模淬火后的平面度70%以上≥0.20mm,热处理工序间产品合格率过低。且原有工艺采取压模淬火,工装一次压淬一片垫片,生产效能过低。零件示意图见下图1所示。
为提高薄壁垫片刚度,增加淬火变形抗力,改变原有机加路线。考虑到该垫片4mm时仍有较大机加余量,垫片厚度调增到8mm,垫片的上下两侧端面同步渗碳。经压模淬火后,垫片淬火变形得到很好的控制,100%的垫片平面度≤0.10mm。
由于16Cr3NiWMoVNbE材料淬透性良好,拟通过多片垫片串联方式,一次压淬多片,以进一步提高生产效能。
压模淬火1次仅压淬1件垫片时,仅为保证平面度一个行为公差,通常不设计淬火心轴。当多片垫片串联方式、叠放在一起淬火,需要设计淬火心轴,进行中心限位。
结合16Cr3NiWMoVNbE材料淬透性,一次尝试4片增厚垫片串联压淬。淬火心轴轴向高度选取30mm。垫片内径部位模量在0.20mm左右,考虑到4片增厚垫片串联压淬时,零件整体径向收缩,抱紧下模淬火心轴,为便于下模淬火心轴工装的拆卸,增厚垫片内径=下模工装心轴直径×1.002,取68.65mm。
压模淬火工装进行压淬前,淬火流油预热20min。增厚垫片压模淬火结束后,进行上下端面的平面度检测,均小于0.10mm,满足工艺要求。经线切割“一分为二”、磨削加工后,薄壁垫片渗层层深一致性较好,满足工序间要求。
本发明的技术效果是:本发明一种形状不规则对称精密薄壁垫片淬火变形精确控制的工艺方法,通过改善局部渗碳零件淬火冷却特性、增加组件刚度,将2片薄壁垫片“合二为一”,两侧同步渗碳后,进行淬火,再使用线切割“一分为二”,提高了航空精密薄壁垫片的淬火变形控制精度;同时,合理的开展压模淬火工装优化设计,并利用固体传递压力的原理,将淬火保温结束后的多片薄壁垫片串联放入淬火心轴,进行压模淬火,解决了原有淬火压床一次只能压淬一片薄壁垫片的技术难题,提升了淬火压床的使用效能。
Claims (8)
1.一种形状不规则对称薄壁垫片淬火变形控制的工艺方法,其特征在于,所述方法包括:
S1,将两片薄壁垫片合二为一,并补偿线切割刀口和磨削修正余量;
S2,从而将两片薄壁垫片加工成组合垫片,对所述组合垫片两侧端面同步进行渗碳;
S3,对多个组合垫片进行压模淬火;
S4,将组合垫片一分为二,切割为两片薄壁垫片,转入机加工序,进行磨削。
2.根据权利要求1所述的一种形状不规则对称薄壁垫片淬火变形控制的工艺方法,其特征在于,
S1中,补偿补偿线切割刀口和磨削修正余量为(0~2)mm。
3.根据权利要求1所述的一种形状不规则对称薄壁垫片淬火变形控制的工艺方法,其特征在于,
S3中,对多个组合垫片进行压模淬火时,压模淬火工装的尺寸根据待压淬的薄壁垫片的个数进行设计,且多个薄壁垫片串联放置在压模淬火工装的淬火芯轴上。
4.根据权利要求3所述的一种形状不规则对称薄壁垫片淬火变形控制的工艺方法,其特征在于,
所述淬火芯轴串装轴向高度大于(n-1)个薄壁垫片厚度,且小于n个薄壁垫片厚度,n为待压淬的薄壁垫片的总个数。
5.根据权利要求1所述的一种形状不规则对称薄壁垫片淬火变形控制的工艺方法,其特征在于,
S3中,对多个组合垫片进行压模淬火时,下模工装的芯轴尺寸按照薄壁垫片内径淬火后要求的实际尺寸加工制造。
6.根据权利要求5所述的一种形状不规则对称薄壁垫片淬火变形控制的工艺方法,其特征在于,
所述组合垫片的内径尺寸为下模工装的芯轴直径的1.001~1.01倍。
7.根据权利要求1所述的一种形状不规则对称薄壁垫片淬火变形控制的工艺方法,其特征在于,
S3中,使用压模淬火工装进行压模淬火时,需通过淬火压床淬火流油对压模淬火工装进行预热。
8.根据权利要求1所述的一种形状不规则对称薄壁垫片淬火变形控制的工艺方法,其特征在于,在S3之后,且在S4之前,所述方法还包括:
对组合垫片进行渗碳淬火之后,还需要进行冰冷及回火处理。
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