Maka pipeline gas dị anya, iji ọkpọkọ ọkpọkọ dị elu bụ ụzọ isi chekwaa ego.Omume ụlọ ọrụ pipeline nke Canada gosipụtara na: ma e jiri ya tụnyere X60, enwere ike ibelata ịdị arọ nke mgbidi pipeline X70 14%, ma e jiri ya tụnyere X70, nnabata nke mgbidi pipeline X80 nwere ike belata site na 12.5%.Ịgbado ọkụ bụ otu n'ime isi njikọ na ígwè ọkpọkọ n'ichepụta na pipeline ewu, n'ihi na-ezighị ezi ịgbado ọkụ thermal okirikiri, na ịgbado ọkụ okpomọkụ metụtara mpaghara (HAZ) bụ adịghị ike akụkụ nke pipeline.Ọnụego jụrụ oyi bụ isi ihe iji chọpụta arụmọrụ nzukọ HAZ, ọ metụtara ntinye ọkụ ịgbado ọkụ, ọkpụrụkpụ nke workpiece na ọnọdụ radieshon gbara ya gburugburu.Ya mere, na-eme ka ezi ịgbado ọkụ usoro, njikwa ịgbado ọkụ ọsọ ọsọ nwere ike nweta magburu onwe nzukọ arụmọrụ nke HAZ, zere HAZ cracks, iji hụ na nchekwa ọrụ nke pipeline.

Site na mmụba nke ọnụego jụrụ oyi, microstructure nke X80 pipeline steel HAZ na-ebute ụzọ na polygonal ferrite, na-ebute ụzọ na B ma ọ bụ ọka nke lath martensite, ike ga-abawanye.Mgbe ntinye ọkụ ịgbado ọkụ buru oke ibu ma ọ bụ ikpo ọkụ dị oke elu yana ọsọ jụrụ oyi dị ala karịa 2℃/ s, X80 pipeline ígwè HAZ nzukọ e nyere mkpa na ma ọ bụ B polygon ferrite grains, ma n'ihi ịdị adị nke pearlite na MA agwaetiti otu ngọngọ nkesa, na-eduga keadighi rarii crystal mmetụta arụmọrụ dara ogbenye.Mgbe ntinye ọkụ ịgbado ọkụ dị obere ma ọ bụ preheating okpomọkụ dị ala na ọsọ jụrụ oyi karịrị 30℃/ s, X80 pipeline ígwè HAZ nzukọ a na-ebute ụzọ na BF ma ọ bụ lamellar martensite, na-akpata mbelata nke arụmọrụ mmetụta kristal na-adịghị mma.Na-eme usoro ịgbado ọkụ ezi uche dị na ya, na-achịkwa ọnụego jụrụ oyi n'ime oke nke 2 ~ 30℃/ s, X80 pipeline ígwè HAZ nzukọ a na-ebute ụzọ B, MA n'àgwàetiti otu na-agbasasị, na keadighi rarii ọka mpaghara nwere kwesịrị ekwesị isi ike na magburu onwe mmetụta arụmọrụ.