磁(ci)粉(fen)(fen)檢測是(shi)一種無損檢測方法,利用(yong)漏磁(ci)場(chang)和缺陷處的磁(ci)粉(fen)(fen)之(zhi)間的相互作用(yong)來顯示鐵磁(ci)材料的表面和近表面缺陷。
磁粉探傷機使(shi)用范(fan)圍:
1、當鐵磁材料的(de)表(biao)面和近表(biao)面尺寸非常(chang)小且間(jian)隙非常(chang)窄時,檢測肉(rou)眼難以看(kan)到的(de)不連續(xu)性;
2、可檢測原(yuan)材(cai)料、半成(cheng)品、成(cheng)品和(he)在役(yi)部件(jian),以及板材(cai)、型材(cai)、管道、棒(bang)材(cai)、焊接(jie)件(jian)、鑄(zhu)鋼件(jian)和(he)鍛(duan)鋼件(jian),并可發現裂紋、夾雜物(wu)、發紋、白點、褶皺(zhou)、冷隔和(he)松(song)動(dong)等缺陷(xian)。
磁(ci)(ci)(ci)(ci)(ci)粉(fen)探(tan)傷機主(zhu)要(yao)用于檢(jian)測表面(mian)(mian)缺陷(xian)。磁(ci)(ci)(ci)(ci)(ci)粉(fen)探(tan)傷利(li)用工(gong)件缺陷(xian)處(chu)的(de)(de)(de)漏磁(ci)(ci)(ci)(ci)(ci)場(chang)(chang)與磁(ci)(ci)(ci)(ci)(ci)粉(fen)之(zhi)間(jian)的(de)(de)(de)相互作用。它利(li)用了鋼制品表面(mian)(mian)和近表面(mian)(mian)缺陷(xian)的(de)(de)(de)磁(ci)(ci)(ci)(ci)(ci)導(dao)(dao)率與鋼的(de)(de)(de)磁(ci)(ci)(ci)(ci)(ci)導(dao)(dao)率之(zhi)間(jian)的(de)(de)(de)差異(yi)。磁(ci)(ci)(ci)(ci)(ci)化后,這(zhe)些材料的(de)(de)(de)不連續(xu)處(chu)的(de)(de)(de)磁(ci)(ci)(ci)(ci)(ci)場(chang)(chang)會發生(sheng)扭曲,在工(gong)件表面(mian)(mian)的(de)(de)(de)漏磁(ci)(ci)(ci)(ci)(ci)部分形(xing)(xing)成漏磁(ci)(ci)(ci)(ci)(ci)場(chang)(chang),從(cong)而吸引磁(ci)(ci)(ci)(ci)(ci)粉(fen)缺陷(xian)處(chu)的(de)(de)(de)磁(ci)(ci)(ci)(ci)(ci)粉(fen)堆積(ji)磁(ci)(ci)(ci)(ci)(ci)痕。在適(shi)當的(de)(de)(de)照明條(tiao)件下,顯示缺陷(xian)位置(zhi)和形(xing)(xing)狀。觀察并解(jie)釋磁(ci)(ci)(ci)(ci)(ci)粉(fen)堆積(ji),實現磁(ci)(ci)(ci)(ci)(ci)粉(fen)探(tan)傷。
磁粉探傷機檢(jian)查鍛(duan)件(jian)(jian)的(de)(de)常見缺陷。鍛(duan)造過程(cheng)中(zhong)(zhong)(zhong),當切割頭不(bu)足時,工件(jian)(jian)錠(ding)中(zhong)(zhong)(zhong)會(hui)出現縮(suo)孔,縮(suo)孔主(zhu)要(yao)出現在鍛(duan)件(jian)(jian)末端。當鋼(gang)錠(ding)在凝(ning)固收縮(suo)過程(cheng)中(zhong)(zhong)(zhong)不(bu)致密且空(kong)洞未溶解時,會(hui)發生松動,主(zhu)要(yao)存在于鋼(gang)錠(ding)的(de)(de)中(zhong)(zhong)(zhong)間(jian)(jian)和頭部(bu)。夾雜(za)(za)物(wu)包括內(nei)部(bu)夾雜(za)(za)物(wu)、外(wai)部(bu)非金屬夾雜(za)(za)物(wu)和金屬夾雜(za)(za)物(wu),主(zhu)要(yao)發生在鑄(zhu)錠(ding)的(de)(de)中(zhong)(zhong)(zhong)間(jian)(jian)和頭部(bu)。裂(lie)紋(wen)(wen)包括鑄(zhu)造裂(lie)紋(wen)(wen)、鍛(duan)造裂(lie)紋(wen)(wen)和熱(re)處(chu)理(li)裂(lie)紋(wen)(wen),這些(xie)裂(lie)紋(wen)(wen)是(shi)由于鍛(duan)造和熱(re)處(chu)理(li)不(bu)當造成的(de)(de),大(da)多數出現在鍛(duan)件(jian)(jian)的(de)(de)表面(mian)或中(zhong)(zhong)(zhong)間(jian)(jian)。白點(dian)是(shi)由于鍛(duan)件(jian)(jian)中(zhong)(zhong)(zhong)的(de)(de)氫含量(liang)高(gao),以(yi)及鍛(duan)造后(hou)冷卻過快,沒(mei)有足夠的(de)(de)時間(jian)(jian)讓(rang)氫逸出,主(zhu)要(yao)集中(zhong)(zhong)(zhong)在鍛(duan)件(jian)(jian)大(da)截面(mian)的(de)(de)中(zhong)(zhong)(zhong)間(jian)(jian)。