鋼波紋涵管布氏(shi)硬(ying)度布氏(shi)硬(ying)度試驗(yan)是用一(yi)定(ding)(ding)的(de)載(zai)荷F,將直徑為D的(de)淬火鋼球或(huo)硬(ying)質合金球,在一(yi)定(ding)(ding)壓(ya)力作用下(xia),壓(ya)人(ren)被測材(cai)料(liao)的(de)表面保持一(yi)定(ding)(ding)的(de)時(shi)間后卸(xie)去(qu)載(zai)荷,以載(zai)荷與壓(ya)痕(hen)表面積的(de)比(bi)值作為布氏(shi)硬(ying)度值,用HBS或(huo)HBW表示,如180HBS、250HBW等,其單位為kgf/mm2,但一(yi)般都不標出。
材料的韌性對鋼波紋管的產品表現至關重要
波紋涵管(guan)目前工程(cheng)上通(tong)常用櫻錘(chui)(chui)沖(chong)(chong)擊試(shi)(shi)(shi)驗來丈量材料的(de)沖(chong)(chong)擊韌性(xing),其原理(li),先(xian)將被(bei)測材料制成一(yi)定外(wai)形和(he)尺寸的(de)試(shi)(shi)(shi)樣(yang)(yang),安放在沖(chong)(chong)擊試(shi)(shi)(shi)驗機上,把具有一(yi)定重量的(de)櫻錘(chui)(chui)提到高度,此時擺(bai)(bai)錘(chui)(chui)位能(neng)為(wei),然后讓(rang)其自有著落(luo),沖(chong)(chong)斷試(shi)(shi)(shi)樣(yang)(yang),沖(chong)(chong)斷試(shi)(shi)(shi)樣(yang)(yang)后擺(bai)(bai)錘(chui)(chui)剩余的(de)能(neng)量為(wei)gH2,擺(bai)(bai)錘(chui)(chui)沖(chong)(chong)斷試(shi)(shi)(shi)樣(yang)(yang)所消(xiao)耗的(de)位能(neng)為(wei)沖(chong)(chong)擊吸(xi)收功,用符號(hao)Akv表示,單位為(wei)J,即Akv=g(H1-H2)J。
鋼波紋涵管
波(bo)紋(wen)涵管洛氏(shi)硬(ying)(ying)度(du)(du)法的長處:丈(zhang)量簡樸、迅速(su),并(bing)可測薄(bo)的試樣(yang)(yang)和(he)硬(ying)(ying)的材(cai)料(liao)(liao),但不(bu)如用(yong)布(bu)氏(shi)硬(ying)(ying)度(du)(du)法正確。當(dang)HBS>220時(shi),HRC/HBS約即是1/10。波(bo)紋(wen)涵管硬(ying)(ying)度(du)(du)也是材(cai)料(liao)(liao)重要(yao)的力學機能(neng)指標(biao),硬(ying)(ying)度(du)(du)和(he)強度(du)(du)一樣(yang)(yang),都反映了材(cai)料(liao)(liao)對(dui)塑性變形的抗力,硬(ying)(ying)度(du)(du)試驗方法較簡樸,又不(bu)損壞零件,故(gu)在出(chu)產實踐中往往通過測定材(cai)料(liao)(liao)的硬(ying)(ying)度(du)(du)來估算(suan)其強度(du)(du)指標(biao)。
洛(luo)氏(shi)硬(ying)度(du)(du)(du)值可(ke)(ke)從洛(luo)氏(shi)硬(ying)度(du)(du)(du)計刻度(du)(du)(du)盤上直接讀出(chu)。波紋涵管用(yong)洛(luo)氏(shi)硬(ying)度(du)(du)(du)計可(ke)(ke)以丈(zhang)量從軟到硬(ying)的(de)(de)各種不同(tong)(tong)材料,這是由于它采用(yong)了不同(tong)(tong)的(de)(de)壓頭和載荷(he)(he),組成(cheng)各種不同(tong)(tong)的(de)(de)洛(luo)氏(shi)硬(ying)度(du)(du)(du)標尺,如(ru)HRA、HRB、HRC等。一般出(chu)產以HRC(用(yong)120度(du)(du)(du)金剛石圓錐(zhui)體作壓頭,載荷(he)(he)為(wei)1500N)用(yong)得多,波紋涵管硬(ying)度(du)(du)(du)值的(de)(de)標注方法與布氏(shi)硬(ying)度(du)(du)(du)相同(tong)(tong),硬(ying)度(du)(du)(du)值的(de)(de)有效范(fan)圍為(wei)20~70HRC。
鋼波紋涵管硬度還影響到材(cai)料(liao)的耐磨性,在(zai)一(yi)般情況下(xia),硬度高(gao)時其耐磨機能(neng)也(ye)較好。波(bo)紋涵(han)管(guan)(guan)沖(chong)擊(ji)韌(ren)性波(bo)紋涵(han)管(guan)(guan)沖(chong)擊(ji)韌(ren)性是(shi)指(zhi)材(cai)料(liao)抵(di)擋沖(chong)擊(ji)載荷的能(neng)力。波(bo)紋涵(han)管(guan)(guan)不少機器零件,如沖(chong)床的連桿、鍛(duan)錘(chui)的錘(chui)頭、火車掛(gua)鉤(gou)、沖(chong)模等,在(zai)工作時要(yao)承(cheng)受沖(chong)擊(ji)載荷、假如仍(reng)用靜載荷作用下(xia)的強度極限(xian)指(zhi)標來進行設(she)計計算,就不能(neng)保證這些零件工作時的安全(quan)性,必需(xu)同時考慮材(cai)料(liao)的韌(ren)性。
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