本文選題：氣門 + 磨損��； 參考：《華南理工大學》2016年碩士論文

【摘要】：氣門是發(fā)動機配氣機構中的關鍵部件之一。氣門服役時承受著高溫、沖擊、摩擦磨損和腐蝕等惡劣工況,需要用高溫強度高,抗機械沖擊和熱沖擊性能好的高溫合金鋼來制備。雖然國內、外不斷有新的氣門材料被開發(fā)使用,但是其成本價格也不斷上升,新的材料性能提高顯著,但仍不能滿足氣門工作條件。在氣門不同的受熱和受力關鍵部位進行不同的表面強化,提高氣門性能并且降低氣門材料總體成本,是氣門綜合性能提高的有效方法。論文對CP169氣門的應力模擬和溫度場分布進行了研究,對懷集登云汽配股份有限公司的失效氣門作統計分析,以此對氣門的盤頭錐面,氣門桿和氣門桿端面的表面強化進行了研究,得出結論如下:CP169氣門的最高溫度為575℃,位于氣門的盤底部,其次高溫為530℃,在氣門的R位位置。氣門的桿部工作溫度較低,在200℃以下,根據實際情況,這些部位的溫度均為冷熱交替溫度,會形成熱疲勞。氣門的最大拉應力出現在氣門頭部R圓弧處,為121MPa;最大壓應力出現在氣門錐面與氣門座圈接觸處,為56.3MPa,氣門在實際工作時反復高速開啟與閉合,屬于疲勞應力。統計分析了懷集登云汽配股份有限公司氣門的失效模式及原因,著重分析了氣門的表面失效,提出了氣門表面失效的防控方法-是加強氣門表面強化處理。對氣門盤錐面堆焊T400超硬合金粉工藝進行探索。多次工藝試驗優(yōu)化堆焊工藝參數,解決了4Cr10Si2Mo材料氣門盤錐面堆焊T400合金粉出現氣孔、夾渣、焊不透等缺陷問題。采用感應加熱去應力方法對堆焊T400合金粉氣門進行退火,解決了堆焊氣門由于存在拉應力而盤部及時開裂的技術問題。針對氣門的特點,開發(fā)了一種快速檢測氣門盤部應力的方法。對CP169氣門表面電鍍厚鉻的研究,采用管形陽極快速鍍鉻,大大提高了氣門桿部的鍍鉻層厚度均勻性,減少了鍍鉻后的精磨工序,降低了生產成本,使公司的氣門鍍鉻技術上了一個新的臺階。對CP169氣門帽形淬火工序的調查研究,發(fā)現其工序能力不足,提出了改進措施。改進措施實施后,CP169氣門帽形淬火工序能力達到客戶的要求,即CPK值達到1.33以上。用改進的表面強化工藝對CP169氣門各部位分別強化,在主機廠進行了多種臺架試驗后,氣門在規(guī)定時間內穩(wěn)定可靠;其后小批量供貨試驗也完全滿足了客戶要求,目前已經大批量供貨,氣門綜合使用性能已達到進口件。
[Abstract]:Valve is one of the key components of engine valve. The valve is subjected to high temperature, impact, friction and corrosion, etc. It is necessary to prepare high temperature alloy steel with high temperature strength, good mechanical impact resistance and thermal shock resistance. Although new valve materials have been developed and used in China and abroad, the cost and price of the new materials are also rising, and the performance of the new materials has been improved significantly, but they still can not meet the working conditions of the valves. It is an effective method to improve the comprehensive performance of the valve by strengthening the valve surface at different heating and stress points to improve the valve performance and reduce the total cost of valve material. In this paper, the stress simulation and temperature field distribution of CP169 valve are studied, and the failure valve of Waiji Dengyun Auto parts Co., Ltd. is statistically analyzed. The surface strengthening of the valve rod and the end surface of the valve rod has been studied. The conclusion is as follows: the highest temperature of the valve is 575 鈩，

本文編號：2005205