???? ???? Alloy20 ???? ?????? ????? ????
???? ???? Shijiazhuang Deye Piping Industries Co., Ltd. ?????? ????? Alloy20 ????? ??????? ????? ?????? ?????? ?????? ???????? ?? ????????? ???????? ??????. ??? ????? ???????? ??????? Alloy20 ?????? ??? ???????? ????????? ?????? ????? ????? ?????? ????? ????? ????? ????? ?????? ??? ?? ???? Alloy20 ????????? ?? ???????? ??????? ????? ?????? ????????? ???????? ??????? ??? ?????? ?????? ????????? ?? ??????? ??????? ?????? ??? ????? ?????? ?????? ??????????? ?????? ??????????????? ?????????? ???????. ??? ???????? ??????? ?????? ??????? ?? ?????? ????? ?? ??????? ???????? ????????? ??????? ??????? ??????? ??? ???? ???? ??????? ?????? ?????? ?? ??????? ?? ???? ??????? ??????? ???????? ?????? ?????? ???????? ???? ???????? ??????? Alloy20 ?????? ??? ??????? ??????? ??????? ?? ??????? ?? ???? ?????? ?? ??? ?????? ?? ?????. ??? ?????? ?? ?????? ?????? ?? ??????? ?????????? ?????? ????????? ??????? ???????? ???????? ????????. ?? ?? ???? Shijiazhuang Deye Piping Industries Co., Ltd. ?????? ??? ???????? ??????? Alloy20 ????? ?????? ???? ???? ?????? ??????? ?????? ??????